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Institute of Architecture of Application Systems : Publications

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@inproceedings {INPROC-2020-49,
   author = {Vladimir Yussupov and Uwe Breitenb{\"u}cher and Christoph Krieger and Frank Leymann and Jacopo Soldani and Michael Wurster},
   title = {{Pattern-based Modelling, Integration, and Deployment of Microservice Architectures}},
   booktitle = {Proceedings of the 2020 IEEE 24th International Enterprise Distributed Object Computing Conference (EDOC 2020)},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {40--50},
   type = {Conference Paper},
   month = {October},
   year = {2020},
   doi = {10.1109/EDOC49727.2020.00015},
   keywords = {Microservice Architecture; Service Composition; Enterprise Integration Pattern; Model-driven Engineering},
   language = {English},
   cr-category = {D.2.2 Software Engineering Design Tools and Techniques,     D.2.11 Software Engineering Software Architectures},
   ee = {https://is.ieis.tue.nl/edoc20/},
   contact = {Vladimir Yussupov yussupov@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Microservice-based architectures (MSAs) gained momentum in industrial and research communities since finer-grained and more independent components foster reuse and reduce time to market. However, to come from the design of MSAs to running applications, substantial knowledge and technology-specific expertise in the deployment and integration of microservices is needed. In this paper, we propose a model-driven and pattern-based approach for composing microservices, which facilitates the transition from architectural models to running deployments. Using a unified modelling for MSAs, including both their integration based on Enterprise Integration Patterns (EIPs) and deployment aspects, our approach enables automatically generating the artefacts for deploying microservice compositions. This helps abstracting away the underlying infrastructure including container orchestration platforms and middleware layer for service integration. To validate the feasibility of our approach, we illustrate its prototypical implementation, with Kubernetes used as container orchestration system and OpenFaaS used for managing integration logic, and we present a case study.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2020-49&engl=1}
}
@inproceedings {INPROC-2020-46,
   author = {Michael Wurster and Uwe Breitenb{\"u}cher and Lukas Harzenetter and Frank Leymann and Jacopo Soldani},
   title = {{TOSCA Lightning: An Integrated Toolchain for Transforming TOSCA Light into Production-Ready Deployment Technologies}},
   booktitle = {Advanced Information Systems Engineering (CAiSE Forum 2020)},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {138--146},
   type = {Demonstration},
   month = {August},
   year = {2020},
   doi = {10.1007/978-3-030-58135-0_12},
   language = {English},
   cr-category = {D.2.2 Software Engineering Design Tools and Techniques},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The OASIS standard TOSCA provides a portable means for specifying multi-service applications and automating their deployment. Despite TOSCA is widely used in research, it is currently not supported by the production-ready deployment technologies daily used by practitioners, hence resulting in a gap between the state-of-the-art in research and the state-of-practice in industry. To help bridging this gap, we identified TOSCA Light, a subset of TOSCA enabling the transformation of compliant deployment models to the vast majority of deployment technology-specific models used by practitioners nowadays. In this paper, we demonstrate TOSCA Lightning by two contributions. We (i) present an integrated toolchain for specifying multi-service applications with TOSCA Light and transforming them into different production-ready deployment technologies. Additionally, we (ii) demonstrate the toolchain's effectiveness based on a third-party application and Kubernetes.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2020-46&engl=1}
}
@inproceedings {INPROC-2020-44,
   author = {Michael Wurster and Uwe Breitenb{\"u}cher and Lukas Harzenetter and Frank Leymann and Jacopo Soldani},
   title = {{TOSCA Lightning: An Integrated Toolchain for Transforming TOSCA Light into Production-Ready Deployment Technologies}},
   booktitle = {Advanced Information Systems Engineering. CAiSE 2020.},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {138--146},
   type = {Demonstration},
   month = {August},
   year = {2020},
   doi = {10.1007/978-3-030-58135-0_12},
   language = {English},
   cr-category = {C.0 Computer Systems Organization, General,     D.2 Software Engineering},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The OASIS standard TOSCA provides a portable means for specifying multi-service applications and automating their deployment. Despite TOSCA is widely used in research, it is currently not supported by the production-ready deployment technologies daily used by practitioners, hence resulting in a gap between the state-of-the-art in research and the state-of-practice in industry. To help bridging this gap, we identified TOSCA Light, a subset of TOSCA enabling the transformation of compliant deployment models to the vast majority of deployment technology-specific models used by practitioners nowadays. In this paper, we demonstrate TOSCA Lightning by two contributions. We (i) present an integrated toolchain for specifying multi-service applications with TOSCA Light and transforming them into different production-ready deployment technologies. Additionally, we (ii) demonstrate the toolchain's effectiveness based on a third-party application and Kubernetes.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2020-44&engl=1}
}
@inproceedings {INPROC-2020-43,
   author = {Michael Wurster and Uwe Breitenb{\"u}cher and Lukas Harzenetter and Frank Leymann and Jacopo Soldani},
   title = {{TOSCA Lightning: An Integrated Toolchain for Transforming TOSCA Light into Production-Ready Deployment Technologies}},
   booktitle = {Advanced Information Systems Engineering. CAiSE 2020.},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {138--146},
   type = {Demonstration},
   month = {August},
   year = {2020},
   doi = {10.1007/978-3-030-58135-0_12},
   language = {English},
   cr-category = {C.0 Computer Systems Organization, General,     D.2 Software Engineering},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The OASIS standard TOSCA provides a portable means for specifying multi-service applications and automating their deployment. Despite TOSCA is widely used in research, it is currently not supported by the production-ready deployment technologies daily used by practitioners, hence resulting in a gap between the state-of-the-art in research and the state-of-practice in industry. To help bridging this gap, we identified TOSCA Light, a subset of TOSCA enabling the transformation of compliant deployment models to the vast majority of deployment technology-specific models used by practitioners nowadays. In this paper, we demonstrate TOSCA Lightning by two contributions. We (i) present an integrated toolchain for specifying multi-service applications with TOSCA Light and transforming them into different production-ready deployment technologies. Additionally, we (ii) demonstrate the toolchain's effectiveness based on a third-party application and Kubernetes.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2020-43&engl=1}
}
@inproceedings {INPROC-2020-42,
   author = {Michael Wurster and Uwe Breitenb{\"u}cher and Lukas Harzenetter and Frank Leymann and Jacopo Soldani},
   title = {{TOSCA Lightning: An Integrated Toolchain for Transforming TOSCA Light into Production-Ready Deployment Technologies}},
   booktitle = {Advanced Information Systems Engineering. CAiSE 2020.},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {138--146},
   type = {Demonstration},
   month = {August},
   year = {2020},
   doi = {10.1007/978-3-030-58135-0_12},
   language = {English},
   cr-category = {C.0 Computer Systems Organization, General,     D.2 Software Engineering},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The OASIS standard TOSCA provides a portable means for specifying multi-service applications and automating their deployment. Despite TOSCA is widely used in research, it is currently not supported by the production-ready deployment technologies daily used by practitioners, hence resulting in a gap between the state-of-the-art in research and the state-of-practice in industry. To help bridging this gap, we identified TOSCA Light, a subset of TOSCA enabling the transformation of compliant deployment models to the vast majority of deployment technology-specific models used by practitioners nowadays. In this paper, we demonstrate TOSCA Lightning by two contributions. We (i) present an integrated toolchain for specifying multi-service applications with TOSCA Light and transforming them into different production-ready deployment technologies. Additionally, we (ii) demonstrate the toolchain's effectiveness based on a third-party application and Kubernetes.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2020-42&engl=1}
}
@inproceedings {INPROC-2020-41,
   author = {Michael Wurster and Uwe Breitenb{\"u}cher and Lukas Harzenetter and Frank Leymann and Jacopo Soldani},
   title = {{TOSCA Lightning: An Integrated Toolchain for Transforming TOSCA Light into Production-Ready Deployment Technologies}},
   booktitle = {Advanced Information Systems Engineering. CAiSE 2020.},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {138--146},
   type = {Demonstration},
   month = {August},
   year = {2020},
   doi = {10.1007/978-3-030-58135-0_12},
   language = {English},
   cr-category = {C.0 Computer Systems Organization, General,     D.2 Software Engineering},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The OASIS standard TOSCA provides a portable means for specifying multi-service applications and automating their deployment. Despite TOSCA is widely used in research, it is currently not supported by the production-ready deployment technologies daily used by practitioners, hence resulting in a gap between the state-of-the-art in research and the state-of-practice in industry. To help bridging this gap, we identified TOSCA Light, a subset of TOSCA enabling the transformation of compliant deployment models to the vast majority of deployment technology-specific models used by practitioners nowadays. In this paper, we demonstrate TOSCA Lightning by two contributions. We (i) present an integrated toolchain for specifying multi-service applications with TOSCA Light and transforming them into different production-ready deployment technologies. Additionally, we (ii) demonstrate the toolchain's effectiveness based on a third-party application and Kubernetes.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2020-41&engl=1}
}
@inproceedings {INPROC-2020-40,
   author = {Michael Wurster and Uwe Breitenb{\"u}cher and Lukas Harzenetter and Frank Leymann and Jacopo Soldani},
   title = {{TOSCA Lightning: An Integrated Toolchain for Transforming TOSCA Light into Production-Ready Deployment Technologies}},
   booktitle = {Advanced Information Systems Engineering. CAiSE 2020.},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {138--146},
   type = {Demonstration},
   month = {August},
   year = {2020},
   doi = {10.1007/978-3-030-58135-0_12},
   language = {English},
   cr-category = {C.0 Computer Systems Organization, General,     D.2 Software Engineering},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The OASIS standard TOSCA provides a portable means for specifying multi-service applications and automating their deployment. Despite TOSCA is widely used in research, it is currently not supported by the production-ready deployment technologies daily used by practitioners, hence resulting in a gap between the state-of-the-art in research and the state-of-practice in industry. To help bridging this gap, we identified TOSCA Light, a subset of TOSCA enabling the transformation of compliant deployment models to the vast majority of deployment technology-specific models used by practitioners nowadays. In this paper, we demonstrate TOSCA Lightning by two contributions. We (i) present an integrated toolchain for specifying multi-service applications with TOSCA Light and transforming them into different production-ready deployment technologies. Additionally, we (ii) demonstrate the toolchain's effectiveness based on a third-party application and Kubernetes.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2020-40&engl=1}
}
@inproceedings {INPROC-2020-34,
   author = {Christoph Krieger and Uwe Breitenb{\"u}cher and Michael Falkenthal and Frank Leymann and Vladimir Yussupov and Uwe Zdun},
   title = {{Monitoring Behavioral Compliance with Architectural Patterns Based on Complex Event Processing}},
   booktitle = {Proceedings of the 8th European Conference on Service-Oriented and Cloud Computing (ESOCC 2020)},
   publisher = {Springer International Publishing},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {125--140},
   type = {Conference Paper},
   month = {March},
   year = {2020},
   doi = {10.1007/978-3-030-44769-4_10},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Architectural patterns assist in the process of architectural decision making as they capture architectural aspects of proven solutions. In many cases, the chosen patterns have system-wide implications on non-functional requirements such as availability, performance, and resilience. Ensuring compliance with the selected patterns is of vital importance to avoid architectural drift between the implementation and its desired architecture. Most of the patterns not only capture structural but also significant behavioral architectural aspects that need to be checked. In case all properties of the system are known before runtime, static compliance checks of application code and configuration files might be sufficient. However, in case aspects of the system dynamically evolve, e.g., due to manual reconfiguration, compliance with the architectural patterns also needs to be monitored during runtime. In this paper, we propose to link compliance rules to architectural patterns that specify behavioral aspects of the patterns based on runtime events using stream queries. These queries serve as input for a complex event processing component to automatically monitor architecture compliance of a running system. To validate the practical feasibility, we applied the approach to a set of architectural patterns in the domain of distributed systems and prototypically implemented a compliance monitor.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2020-34&engl=1}
}
@inproceedings {INPROC-2020-33,
   author = {Karoline Wild and Uwe Breitenb{\"u}cher and K{\'a}lm{\'a}n K{\'e}pes and Frank Leymann and Benjamin Weder},
   title = {{Decentralized Cross-Organizational Application Deployment Automation: An Approach for Generating Deployment Choreographies Based on Declarative Deployment Models}},
   booktitle = {Proceedings of the 32nd Conference on Advanced Information Systems Engineering (CAiSE 2020)},
   publisher = {Springer International Publishing},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science},
   volume = {12127},
   pages = {20--35},
   type = {Conference Paper},
   month = {June},
   year = {2020},
   isbn = {10.1007/978-3-030-49435-3_2},
   keywords = {Distributed Application; Deployment; Choreography; TOSCA; BPEL},
   language = {English},
   cr-category = {D.2.2 Software Engineering Design Tools and Techniques,     D.2.11 Software Engineering Software Architectures},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Various technologies have been developed to automate the deployment of applications. Although most of them are not limited to a specific infrastructure and able to manage multi-cloud applications, they all require a central orchestrator that processes the deployment model and executes all necessary tasks to deploy and orchestrate the application components on the respective infrastructure. However, there are applications in which several organizations, such as different departments or even different companies, participate. Due to security concerns, organizations typically do not expose their internal APIs to the outside or leave control over application deployments to others. As a result, centralized deployment technologies are not suitable to deploy cross-organizational applications. In this paper, we present a concept for the decentralized cross-organizational application deployment automation. We introduce a global declarative deployment model that describes a composite cross-organizational application, which is split to local parts for each participant. Based on the split declarative deployment models, workflows are generated which form the deployment choreography and coordinate the local deployment and cross-organizational data exchange. To validate the practical feasibility, we prototypical implemented a standard-based end-to-end toolchain for the proposed method using TOSCA and BPEL.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2020-33&engl=1}
}
@inproceedings {INPROC-2020-27,
   author = {Ghareeb Falazi and Uwe Breitenb{\"u}cher and Florian Daniel and Florian Lamparelli and Frank Leymann and Vladimir Yussupov},
   title = {{Smart Contract Invocation Protocol (SCIP): A Protocol for the Uniform Integration of Heterogeneous Blockchain Smart Contracts}},
   booktitle = {CAiSE 2020: Advanced Information Systems Engineering},
   editor = {Schahram Dustdar and Eric Yu and Camille Salinesi and Dominique Rieu and Vik Pant},
   address = {Cham},
   publisher = {Springer International Publishing},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science},
   volume = {12127},
   pages = {134--149},
   type = {Conference Paper},
   month = {June},
   year = {2020},
   doi = {10.1007/978-3-030-49435-3_9},
   keywords = {Smart Contract Invocation Protocol; SCIP; SCL; SCDL; Blockchain; Smart Contract; Integration},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     D.2.11 Software Engineering Software Architectures,     D.2.12 Software Engineering Interoperability},
   ee = {http://caise20.imag.fr/},
   contact = {Ghareeb Falazi ghareeb.falazi@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Blockchains are distributed ledgers that enable the disintermediation of collaborative processes and, at the same time, foster trust among partners. Modern blockchains support smart contracts, i.e., software deployed on the blockchain, and guarantee their repeatable, deterministic execution. Alas, blockchains and smart contracts lack standardization. Therefore, smart contracts come with heterogeneous properties, APIs and data formats. This hinders the integration of smart contracts running in different blockchains, e.g., into enterprise business processes. This paper introduces the Smart Contract Invocation Protocol (SCIP), which unifies interacting with smart contracts of different blockchains. The protocol supports invoking smart contract functions, monitoring function executions, emitted events, and transaction finality, as well as querying a blockchain. The protocol is accompanied by a prototypical implementation of a SCIP endpoint in the form of a gateway.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2020-27&engl=1}
}
@inproceedings {INPROC-2020-26,
   author = {Michael Wurster and Uwe Breitenb{\"u}cher and Lukas Harzenetter and Frank Leymann and Jacopo Soldani and Vladimir Yussupov},
   title = {{TOSCA Light: Bridging the Gap between the TOSCA Specification and Production-ready Deployment Technologies}},
   booktitle = {Proceedings of the 10th International Conference on Cloud Computing and Services Science (CLOSER)},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {216--226},
   type = {Conference Paper},
   month = {May},
   year = {2020},
   doi = {10.5220/0009794302160226},
   language = {German},
   cr-category = {C.0 Computer Systems Organization, General,     D.2 Software Engineering},
   contact = {Michael Wurster wurster@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The automation of application deployment is critical because manually deploying applications is time-consuming, tedious, and error-prone. Several deployment automation technologies have been developed in recent years employing tool-specific deployment modeling languages. At the same time, the OASIS standard Topology Orchestration Specification for Cloud Applications (TOSCA) emerged as a means for describing cloud applications, i. e., their components and relationships, in a vendor-agnostic fashion. Despite TOSCA is widely used in research, it is not supported by the production-ready deployment automation technologies daily used by practitioners working with cloud-native applications, hence resulting in a gap between the state-of-the-art in research and state-of-practice in the industry. To help bridging this gap, we leverage the recently introduced Essential Deployment Metamodel (EDMM) and identify TOSCA Light, an EDMM-compliant subset of TOSCA, to enact the transformation from TOSCA to the vast majority of deployment automation technology-specific models used by today{\^a}€™s software industry. Further, we present an end-to-end TOSCA Light modeling and transformation workflow and show a prototypical implementation to validate our approach.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2020-26&engl=1}
}
@inproceedings {INPROC-2020-25,
   author = {Michael Wurster and Uwe Breitenb{\"u}cher and Antonio Brogi and Frank Leymann and Jacopo Soldani},
   title = {{Cloud-native Deploy-ability: An Analysis of Required Features of Deployment Technologies to Deploy Arbitrary Cloud-native Applications}},
   booktitle = {Proceedings of the 10th International Conference on Cloud Computing and Services Science (CLOSER)},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {171--180},
   type = {Conference Paper},
   month = {May},
   year = {2020},
   doi = {10.5220/0009571001710180},
   language = {English},
   cr-category = {C.0 Computer Systems Organization, General,     D.2 Software Engineering},
   contact = {Michael Wurster wurster@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The adoption of cloud computing combined with DevOps enables companies to react to new market requirements more rapidly and fosters the use of automation technologies. This influences the way software solutions are built, which is why the concept of cloud-native applications has emerged over the last few years to build highly scalable applications, and to automatically deploy and run them in modern cloud environments. However, there is currently no reference work clearly stating the features that a deployment technology must offer to support the deployment of arbitrary cloud-native applications. In this paper, we derive three essential features for deployment technologies based on the current cloud-native research and characteristics discussed therein. The presented features can be used to compare and categorize existing deployment technologies, and they are intended to constitute a first step towards a comprehensive framework to assess deployment technologies.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2020-25&engl=1}
}
@inproceedings {INPROC-2020-24,
   author = {Vladimir Yussupov and Uwe Breitenb{\"u}cher and Ayhan Kaplan and Frank Leymann},
   title = {{SEAPORT: Assessing the Portability of Serverless Applications}},
   booktitle = {Proceedings of the 10th International Conference on Cloud Computing and Services Science (CLOSER 2020)},
   editor = {Donald Ferguson and Markus Helfert and Claus Pahl},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {456--467},
   type = {Conference Paper},
   month = {May},
   year = {2020},
   doi = {10.5220/0009574104560467},
   language = {English},
   cr-category = {D.2.0 Software Engineering General,     D.2.11 Software Engineering Software Architectures,     D.2.12 Software Engineering Interoperability},
   ee = {http://closer.scitevents.org},
   contact = {Vladimir Yussupov yussupov@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The term serverless is often used to describe cloud applications that comprise components managed by third parties. Like any other cloud application, serverless applications are often tightly-coupled with providers, their features, models, and APIs. As a result, when their portability to another provider has to be assessed, application owners must deal with identification of heterogeneous lock-in issues and provider-specific technical details. Unfortunately, this process is tedious, error-prone, and requires significant technical expertise in the domains of serverless and cloud computing. In this work, we introduce SEAPORT, a method for automatically assessing the portability of serverless applications with respect to a chosen target provider or platform. The method introduces (i) a canonical serverless application model, and (ii) the concepts for portability assessment involving classification and components similarity calculation together with the static code analysis. The method aims to be compatible with existing migration concepts to allow using it as a complementary part for serverless use cases. We present an architecture of a decision support system supporting automated assessment of the given application model with respect to the target provider. To validate the technical feasibility of the method, we implement the system prototypically.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2020-24&engl=1}
}
@inproceedings {INPROC-2020-23,
   author = {Frank Leymann and Johanna Barzen and Michael Falkenthal and Daniel Vietz and Benjamin Weder and Karoline Wild},
   title = {{Quantum in the Cloud: Application Potentials and Research Opportunities}},
   booktitle = {Proceedings of the 10th International Conference on Cloud Computing and Service Science (CLOSER 2020)},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {9--24},
   type = {Conference Paper},
   month = {April},
   year = {2020},
   isbn = {10.5220/0009819800090024},
   keywords = {Cloud Computing; Quantum Computing; Hybrid Applications},
   language = {English},
   cr-category = {D.2.2 Software Engineering Design Tools and Techniques,     J.5 Arts and Humanities},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Quantum computers are becoming real, and they have the inherent potential to significantly impact many application domains. We sketch the basics about programming quantum computers, showing that quantum programs are typically hybrid consisting of a mixture of classical parts and quantum parts. With the advent of quantum computers in the cloud, the cloud is a fine environment for performing quantum programs. The tool chain available for creating and running such programs is sketched. As an exemplary problem we discuss efforts to implement quantum programs that are hardware independent. A use case from machine learning is outlined. Finally, a collaborative platform for solving problems with quantum computers that is currently under construction is presented.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2020-23&engl=1}
}
@inproceedings {INPROC-2020-22,
   author = {Michael Zimmermann and Uwe Breitenb{\"u}cher and Lukas Harzenetter and Frank Leymann and Vladimir Yussupov},
   title = {{Self-Contained Service Deployment Packages}},
   booktitle = {Proceedings of the 10th International Conference on Cloud Computing and Services Science (CLOSER 2020)},
   editor = {Donald Ferguson and Markus Helfert and Claus Pahl},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {371--381},
   type = {Conference Paper},
   month = {May},
   year = {2020},
   isbn = {978-989-758-424-4},
   doi = {10.5220/0009414903710381},
   language = {English},
   cr-category = {C.0 Computer Systems Organization, General,     D.2 Software Engineering},
   ee = {http://closer.scitevents.org/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Complex applications are typically composed of multiple components. In order to install these components all their dependencies need to be satisfied. Typically these dependencies are resolved, downloaded, and installed during the deployment time and in the target environment, e.g., using package manager of the operating system. However, under some circumstances this approach is not applicable, e.g., if the access to the Internet is limited or non-existing at all. For instance, Industry 4.0 environments often have no Internet access for security reasons. Thus, in these cases, deployment packages without external dependencies are required that already contain everything required to deploy the software. In this paper, we present an approach enabling the transformation of non-self-contained deployment packages into self-contained deployment packages. Furthermore, we present a method for developing self-contained deployment packages systematically. The practical feasibility is validated by a prototypical implementation following our proposed system architecture. Moreover, our prototype is evaluated by provisioning a LAMP stack using the open-source ecosystem OpenTOSCA.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2020-22&engl=1}
}
@inproceedings {INPROC-2020-21,
   author = {Michael Zimmermann and Uwe Breitenb{\"u}cher and K{\'a}lm{\'a}n K{\'e}pes and Frank Leymann and Benjamin Weder},
   title = {{Data Flow Dependent Component Placement of Data Processing Cloud Applications}},
   booktitle = {Proceedings of the 2020 IEEE International Conference on Cloud Engineering (IC2E)},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {83--94},
   type = {Conference Paper},
   month = {April},
   year = {2020},
   isbn = {978-1-7281-1099-8},
   doi = {10.1109/IC2E48712.2020.00016},
   language = {English},
   cr-category = {C.0 Computer Systems Organization, General,     D.2 Software Engineering},
   ee = {https://conferences.computer.org/IC2E},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {With the ongoing advances in the area of cloud computing, Internet of Things, Industry 4.0, and the increasing prevalence of cyber-physical systems and devices equipped with sensors, the amount of data generated every second is rising steadily. Thereby, the gathering of data and the creation of added value from this data is getting easier and easier. However, the increasing volume of data stored in the cloud leads to new challenges. Analytics software and scalable platforms are required to evaluate the data distributed all over the internet. But with distributed applications and large data sets to be handled, the network becomes a bottleneck. Therefore, in this work, we present an approach to automatically improve the deployment of such applications regarding the placement of data processing components dependent on the data flow of the application. To show the practical feasibility of our approach, we implemented a prototype based on the open-source ecosystem OpenTOSCA. Moreover, we evaluated our prototype using various scenarios.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2020-21&engl=1}
}
@inproceedings {INPROC-2020-14,
   author = {Philip Schildkamp and Lukas Harzenetter and Uwe Breitenb{\"u}cher and Frank Leymann and Brigitte Mathiak and Claes Neuefeind},
   title = {{Modellierung und Verwaltung von DHAnwendungen in TOSCA}},
   booktitle = {DHd 2020 Spielr{\"a}ume: Digital Humanities zwischen Modellierung und Interpretation. Konferenzabstracts},
   editor = {Christof Sch{\"o}ch},
   publisher = {Zenodo},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {36--38},
   type = {Conference Paper},
   month = {February},
   year = {2020},
   language = {German},
   cr-category = {C.0 Computer Systems Organization, General},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Das aktuell vom Institut f{\"u}r Architektur von Anwendungssystemen (IAAS) der Universit{\"a}t Stuttgart und vom Data Center for the Humanities (DCH) der Universit{\"a}t zu K{\"o}ln bearbeitete Projekt SustainLife {\^a}€“ Erhalt lebender, digitaler Systeme f{\"u}r die Geisteswissenschaften befasst sich mit der Konservierung von Forschungssoftware im Bereich der Digital Humanities (DH). Dabei wird der Topology Orchestration Specification for Cloud Applications (TOSCA) Standard verwendet, um das Deployment von DH-Anwendungen vollst{\"a}ndig zu automatisieren und diese langfristig verf{\"u}gbar zu halten. Um der DH Community unseren Ansatz interaktiv zu demonstrieren, m{\"o}chten wir im Vorfeld der DHd 2020 einen Workshop zur Modellierung und Verwaltung von DH-Anwendungen in TOSCA durchf{\"u}hren. Dabei sollen Kernkompetenzen bez{\"u}glich der Modellierung von Softwaresystemen mit TOSCA sowie Erfahrungen und Best Practices im Umgang mit OpenTOSCA, einer open-source Implementierung des TOSCA Standards, vermittelt werden.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2020-14&engl=1}
}
@inproceedings {INPROC-2020-13,
   author = {Michael Wurster and Uwe Breitenb{\"u}cher and Antonio Brogi and Lukas Harzenetter and Frank Leymann and Jacopo Soldani},
   title = {{Technology-Agnostic Declarative Deployment Automation of Cloud Applications}},
   booktitle = {Service-Oriented and Cloud Computing (ESOCC 2020)},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {97--112},
   type = {Conference Paper},
   month = {March},
   year = {2020},
   doi = {10.1007/978-3-030-44769-4_8},
   language = {English},
   cr-category = {C.0 Computer Systems Organization, General,     D.2 Software Engineering},
   contact = {Michael Wurster wurster@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Declarative approaches for automating the deployment and configuration management of multi-component applications are on the rise. Many deployment technologies exist, sharing the same baselines for enacting declarative deployments, even if based on different languages for specifying multi-component applications. The Essential Deployment Metamodel (EDMM) Modeling and Transformation Framework allows to specify multi-component applications in a technology-agnostic manner, and to automatically generate the technology-specific deployment artifacts allowing to deploy an IaaS-based application. In this paper, we propose an extension of the EDMM Modeling and Transformation Framework to PaaS and SaaS by allowing to deploy application components on PaaS platforms or to implement them by instrumenting SaaS services. Given that not all existing deployment technologies support PaaS and SaaS deployments, we also propose the new EDMM Decision Support Framework allowing us to determine which deployment technologies can be used to deploy an application specified with EDMM.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2020-13&engl=1}
}
@inproceedings {INPROC-2019-43,
   author = {Lukas Reinfurt and Michael Falkenthal and Frank Leymann},
   title = {{A Pattern-Based Method for Designing IoT Systems}},
   booktitle = {Proceedings of the 13th Symposium and Summer School On Service-Oriented Computing (SummerSoc19)},
   publisher = {IBM Research Division},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--27},
   type = {Conference Paper},
   month = {September},
   year = {2019},
   keywords = {Pattern Languages; Design Patterns; Pattern-Based Method; Internet of Things; System Design},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     D.2.11 Software Engineering Software Architectures},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The Internet of Things pattern language can be a valuable tool for practitioners that want to design an IoT system. It offers them abstract proven solutions based on existing real world uses and, thus, makes working with the large amount of different devices, platforms, technologies, and standards in the field of IoT more manageable. Practitioners can use the pattern language to design an IoT system by starting with any pattern they deem suitable and then by continuing to follow the links to related patterns defined by the pattern language. However, when designing an IoT system, applying patterns in a certain order can be beneficial. It allows practitioners to think through important aspects of the system in the right order to minimize context switching and to avoid having to change previous decisions. Thus, we introduce a pattern-based method for designing IoT systems. It guides practitioners through the steps of designing an IoT system in a sensible order. Based on answers to specific questions asked in each step, it points practitioners to suitable patterns and other helpful tools. The result is a pattern-annotated architecture diagram that can be used as basis for further architecture refinement, as a guide for finding existing solutions, and as input for communication with other involved stakeholders.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2019-43&engl=1}
}
@inproceedings {INPROC-2019-42,
   author = {Andrea Lamparelli and Ghareeb Falazi and Uwe Breitenb{\"u}cher and Florian Daniel and Frank Leymann},
   title = {{Smart Contract Locator (SCL) and Smart Contract Description Language (SCDL)}},
   booktitle = {Service-Oriented Computing - ICSOC 2019 Workshops},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science (LNCS)},
   volume = {12019},
   pages = {195--210},
   type = {Workshop Paper},
   month = {October},
   year = {2019},
   doi = {10.1007/978-3-030-45989-5_16},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     D.2.11 Software Engineering Software Architectures,     D.2.12 Software Engineering Interoperability},
   contact = {Ghareeb Falazi ghareeb.falazi@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Today{\^a}€™s blockchain technologies focus mostly on isolated, proprietary technologies, yet there are application scenarios that ask for interoperability, e.g., among blockchains themselves or with external applications. This paper proposes the Smart Contract Locator (SCL) for the unambiguous identification of smart contracts over the Internet and across blockchains, and the Smart Contract Description Language (SCDL) for the abstract description of the external interface of smart contracts. The paper derives a unified metamodel for blockchain smart contract description and equips it with a concrete, JSON-based description language for smart contract search and discovery. The goal of the proposal is to foster smart contract reuse both inside blockchains and through the integration of smart contracts inside enterprise applications. The idea is inspired by the Service-Oriented Architecture (SOA) and aims to provide a high-level, cross-blockchain interoperability layer.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2019-42&engl=1}
}
@inproceedings {INPROC-2019-41,
   author = {Michael Wurster and Uwe Breitenb{\"u}cher and Antonio Brogi and Ghareeb Falazi and Lukas Harzenetter and Frank Leymann and Jacopo Soldani and Vladimir Yussupov},
   title = {{The EDMM Modeling and Transformation System}},
   booktitle = {Service-Oriented Computing - ICSOC 2019 Workshops},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {294--298},
   type = {Demonstration},
   month = {October},
   year = {2019},
   doi = {10.1007/978-3-030-45989-5_26},
   language = {English},
   cr-category = {C.0 Computer Systems Organization, General,     D.2 Software Engineering},
   contact = {Michael Wurster wurster@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Since deployment automation technologies are heterogeneous regarding their supported features and modeling languages, selecting a concrete technology is difficult and can result in a lock-in. Therefore, we presented the Essential Deployment Metamodel (EDMM) in previous work that abstracts from concrete technologies and provides a normalized metamodel for creating technology-independent deployment models. In this demonstration, we present tool support for EDMM in the form of the EDMM Modeling and Transformation System, which enables (i) creating EDMM models graphically and (ii) automatically transforming them into models supported by concrete deployment automation technologies.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2019-41&engl=1}
}
@inproceedings {INPROC-2019-40,
   author = {Karoline Saatkamp and Christoph Krieger and Frank Leymann and Julian Sudendorf and Michael Wurster},
   title = {{Application Threat Modeling and Automated VNF Selection for Mitigation using TOSCA}},
   booktitle = {2019 International Conference on Networked Systems (NetSys)},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--6},
   type = {Workshop Paper},
   month = {October},
   year = {2019},
   isbn = {10.1109/NetSys.2019.8854524},
   keywords = {Threat Modeling; VNF; STRIDE; TOSCA},
   language = {English},
   cr-category = {D.2.2 Software Engineering Design Tools and Techniques},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In the era of Internet of Things (IoT) the interconnectedness of devices, and thus the need to protect them against threats increased. The widely used threat modeling method STRIDE can be used to identify the system's vulnerabilities and to determine appropriate mitigation solutions. In connected environments, especially the network layer plays a critical role in achieving security. Based on the Network Functions Virtualization (NFV) concept, network functions can be virtualized and provisioned on standard IT hardware. Virtualized Network Functions (VNFs) increase the flexibility of the provisioning, and thus security network functions, such as firewalls, can be easily deployed. However, in a complex distributed system it is time-consuming, error-prone, and for application architects even not possible to identify and provision the required security functions. For the orchestration and management of applications the TOSCA modeling language can be used to describe the application's components and their relations in a deployment model. The standard was mainly developed for cloud applications but was extended to the network layer. In this paper, we present a TOSCA-based approach for threat modeling based on STRIDE that facilitates the automated VNF selection and injection into TOSCA deployment models. The feasibility of our approach is validated by an extension of the TOSCA modeling tool Winery.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2019-40&engl=1}
}
@inproceedings {INPROC-2019-38,
   author = {Vladimir Yussupov and Uwe Breitenb{\"u}cher and Frank Leymann and Christian M{\"u}ller},
   title = {{Facing the Unplanned Migration of Serverless Applications: A Study on Portability Problems, Solutions, and Dead Ends}},
   booktitle = {Proceedings of the 12th IEEE/ACM International Conference on Utility and Cloud Computing (UCC 2019)},
   editor = {ACM},
   publisher = {ACM},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {273--283},
   type = {Conference Paper},
   month = {December},
   year = {2019},
   doi = {10.1145/3344341.3368813},
   keywords = {Serverless; Function-as-a-Service; FaaS; Portability; Migration},
   language = {English},
   cr-category = {D.2.0 Software Engineering General,     D.2.11 Software Engineering Software Architectures,     D.2.12 Software Engineering Interoperability},
   ee = {https://www.ucc-conference.org},
   contact = {Vladimir Yussupov yussupov@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Serverless computing focuses on developing cloud applications that comprise components fully managed by providers. Function-as-a-Service (FaaS) service model is often associated with the term serverless as it allows developing entire applications by composing provider-managed, event-driven code snippets. However, such reduced control over the infrastructure and tight-coupling with provider's services amplify the various lock-in problems. In this work, we explore the challenges of migrating serverless, FaaS-based applications across cloud providers. To achieve this, we conduct an experiment in which we implement four prevalent yet intentionally simple serverless use cases and manually migrate them across three popular commercial cloud providers. The results show that even when migrating simple use cases, developers encounter multiple aspects of a lock-in problem. Moreover, we present a categorization of the problems and discuss the feasibility of possible solutions.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2019-38&engl=1}
}
@inproceedings {INPROC-2019-37,
   author = {Vladimir Yussupov and Uwe Breitenb{\"u}cher and Frank Leymann and Michael Wurster},
   title = {{A Systematic Mapping Study on Engineering Function-as-a-Service Platforms and Tools}},
   booktitle = {Proceedings of the 12th IEEE/ACM International Conference on Utility and Cloud Computing (UCC 2019)},
   editor = {ACM},
   publisher = {ACM},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {229--240},
   type = {Conference Paper},
   month = {December},
   year = {2019},
   doi = {10.1145/3344341.3368803},
   keywords = {Serverless; FaaS; Function-as-a-Service; Systematic Mapping Study},
   language = {English},
   cr-category = {C.0 Computer Systems Organization, General,     C.2.4 Distributed Systems,     D.2 Software Engineering},
   ee = {https://www.ucc-conference.org},
   contact = {Vladimir Yussupov yussupov@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Function-as-a-Service (FaaS) is a novel cloud service model allowing to develop fine-grained, provider-managed cloud applications. In this work, we investigate which challenges motivate researchers to introduce or enhance FaaS platforms and tools. We use a systematic mapping study method to collect and analyze the relevant scientific literature, which helps us answering the three clearly-defined research questions. We design our study using well-established guidelines and systematically apply it to 62 selected publications. The collected and synthesized data provides useful insights into the main challenges that motivate researchers to work on this topic and can be helpful in identifying research gaps for future research.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2019-37&engl=1}
}
@inproceedings {INPROC-2019-36,
   author = {Vladimir Yussupov and Uwe Breitenb{\"u}cher and Michael Hahn and Frank Leymann},
   title = {{Serverless Parachutes: Preparing Chosen Functionalities for Exceptional Workloads}},
   booktitle = {Proceedings of the 2019 IEEE 23rd International Enterprise Distributed Object Computing Conference (EDOC 2019)},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {226--235},
   type = {Conference Paper},
   month = {October},
   year = {2019},
   doi = {10.1109/EDOC.2019.00035},
   keywords = {Serverless; FaaS; Function-as-a-Service; Scalability; Failover; Annotation},
   language = {English},
   cr-category = {D.2.2 Software Engineering Design Tools and Techniques,     D.2.11 Software Engineering Software Architectures,     D.3.4 Programming Languages Processors},
   ee = {https://edoc2019.sciencesconf.org/},
   contact = {Vladimir Yussupov yussupov@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Function-as-a-Service (FaaS) is an emerging cloud service model that enables composing applications using arbitrary, small, and event-driven code snippets managed by cloud providers and that can be scaled to zero. The scalability properties of FaaS look attractive for handling rare or unexpected high loads that affect only particular functionalities of the application. However, deciding on the component granularity upfront or reengineering the architecture of an entire application for rare workloads is often a very difficult challenge or even infeasible. In this work, we introduce a method that prepares annotated functionalities for handling rare workloads by automatically extracting them from the source code of the application and additionally deploying them as FaaS functions, while keeping the original application's functionalities and architecture unchanged. In this way, the benefits of FaaS can be leveraged without the need to reengineer the application only for rare cases. We validate our method by means of a prototype, evaluate its feasibility in a set of experiments, and discuss limitations and future work.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2019-36&engl=1}
}
@inproceedings {INPROC-2019-35,
   author = {Ghareeb Falazi and Michael Hahn and Uwe Breitenb{\"u}cher and Frank Leymann and Vladimir Yussupov},
   title = {{Process-Based Composition of Permissioned and Permissionless Blockchain Smart Contracts}},
   booktitle = {Proceedings of the 2019 IEEE 23rd International Enterprise Distributed Object Computing Conference (EDOC 2019)},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {77--87},
   type = {Conference Paper},
   month = {October},
   year = {2019},
   doi = {10.1109/EDOC.2019.00019},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     D.2.2 Software Engineering Design Tools and Techniques,     D.2.11 Software Engineering Software Architectures},
   ee = {https://edoc2019.sciencesconf.org/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Blockchains are distributed systems that facilitate the interaction of autonomous entities with limited mutual trust. Many of them support transactional applications known as smart contracts, which access and modify the shared world state. Permissionless blockchains are completely decentralized and do not require mutual trust between interacting peers, but at the expense of having low performance and limited data confidentiality capabilities. On the other hand, permissioned blockchains solve these issues, but sacrifice complete decentralization and involve more trust assumptions. Therefore, there is no single blockchain system suitable for all use-cases. However, this becomes a serious integration challenge for enterprises that need to interact with multiple permissioned and permissionless blockchains in the same context. To facilitate this, we propose an approach that enables composing smart contract functions of various permissioned and permissionless blockchain systems by providing the ability to invoke them directly from business process models using a new task type. To keep this task blockchain-agnostic, we designed a generic technique to identify smart contract functions, as well as a generic metric to describe the degree-of-confidence in the finality of blockchain transactions. Thereby, the proposed approach extends our previous work, BlockME, which provides business modeling extensions only suitable for interacting with permissionless blockchains. To validate the practical feasibility of our approach, we provide a detailed system architecture and a prototypical implementation supporting multiple blockchains. Keywords: blockchains, business process management, permissioned blockchains, smart contract composition, blockchain access layer, BlockME2},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2019-35&engl=1}
}
@inproceedings {INPROC-2019-34,
   author = {K{\'a}lm{\'a}n K{\'e}pes and Uwe Breitenb{\"u}cher and Frank Leymann and Karoline Saatkamp and Benjamin Weder},
   title = {{Deployment of Distributed Applications Across Public and Private Networks}},
   booktitle = {Proceedings of the 23rd IEEE International Enterprise Distributed Object Computing Conference (EDOC)},
   address = {Paris},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {236--242},
   type = {Conference Paper},
   month = {October},
   year = {2019},
   issn = {2325-6354},
   doi = {10.1109/EDOC.2019.00036},
   language = {English},
   cr-category = {D.4.4 Operating Systems Communications Management,     D.2.11 Software Engineering Software Architectures,     D.2.9 Software Engineering Management},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The growing usage of software and hardware in our everyday lives has lead to paradigms such as Cloud Computing, Edge Computing, and the Internet of Things. The combination of these paradigms results in distributed and heterogeneous target environments: components of an application often need to be deployed in different environments such as clouds, private data centers, and small devices. This makes the deployment of distributed applications a complex and error-prone challenge as deployment systems have to (i) support cloud deployments, (ii) determine the location of physical resources, (iii) cope with security mechanisms preventing inbound communication, and (iv) use hardware-constrained devices. In this paper, we present an approach for the automated deployment of distributed applications on heterogeneous target environments consisting of public and private clouds, and devices. We especially tackle the issue of deploying components in environments having restricted inbound communication capabilities. We prototypically implemented and compared our approach based on a smart home scenario using TOSCA and the OpenTOSCA Ecosystem.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2019-34&engl=1}
}
@inproceedings {INPROC-2019-33,
   author = {Lukas Harzenetter and Uwe Breitenb{\"u}cher and Frank Leymann and Karoline Saatkamp and Benjamin Weder and Michael Wurster},
   title = {{Automated Generation of Management Workflows for Applications Based on Deployment Models}},
   booktitle = {2019 IEEE 23rd International Enterprise Distributed Object Computing Conference (EDOC)},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {216--225},
   type = {Conference Paper},
   month = {December},
   year = {2019},
   doi = {10.1109/EDOC.2019.00034},
   language = {English},
   cr-category = {D.0 Software General},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {To automate the deployment of applications several deployment technologies have been developed. However, the management of deployed applications is only partially covered by existing approaches: While management functionalities such as scaling components or changing their configurations are covered directly by cloud providers or configuration management technologies such as Chef, holistic management processes that affect multiple components probably deployed in different environments cannot be automated using these approaches. For example, testing all deployed components and their communication or backing up the entire application state that is scattered across different components requires custom management logic that needs to be implemented manually, $\backslash$eg using scripts. However, a manual implementation of such management processes is error-prone, time-consuming, and requires immense technical expertise. Therefore, we propose an approach that enables automatically generating executable management workflows based on the declarative deployment model of an application. This significantly reduces the effort for automating holistic management processes as no manual implementation is required. We validate the practical feasibility of the approach by a prototypical implementation based on the TOSCA standard and the OpenTOSCA ecosystem.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2019-33&engl=1}
}
@inproceedings {INPROC-2019-30,
   author = {Amirali Amiri and Christoph Krieger and Uwe Zdun and Frank Leymann},
   title = {{Dynamic Data Routing Decisions for Compliant Data Handling in Service- and Cloud-Based Architectures: A Performance Analysis}},
   booktitle = {Proceedings of the 2019 IEEE International Conference on Services Computing (SCC)},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {215--219},
   type = {Conference Paper},
   month = {July},
   year = {2019},
   doi = {10.1109/SCC.2019.00044},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     D.2.11 Software Engineering Software Architectures},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In many service-based applications, decisions about data routing need to be made at runtime, for instance to ensure compliant data handling. Different service-and cloud-based architectures to make dynamic data routing decisions exist including central entities, multiple dedicated dynamic router services, or using a sidecar for each involved service. These archi-tectures differ in various quality attributes including complexity, understandability, and changeability of the decision logic. Choosing the wrong architecture for decision-making at runtime may severely impact the performance of the software system. In this paper, we have evaluated the performance of three representative approaches for processing compliance rules concerned with data routing in service-and cloud-based architectures. The results show that distributed approaches for dynamic data routing have a better performance compared to centralized solutions. On the other hand, centralized solutions are easier to understand and change, but this strongly depends on the domain problem.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2019-30&engl=1}
}
@inproceedings {INPROC-2019-29,
   author = {Claes Neuefeind and Philip Schildkamp and Brigitte Mathiak and Aleksander Marcic and Frank Hentschel and Lukas Harzenetter and Johanna Barzen and Uwe Breitenb{\"u}cher and Frank Leymann},
   title = {{Sustaining the Musical Competitions Database: A TOSCA-based Approach to Application Preservation in the Digital Humanities}},
   booktitle = {DH 2019},
   publisher = {DH 2019},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--1},
   type = {Conference Paper},
   month = {March},
   year = {2019},
   language = {English},
   cr-category = {A.0 General Literature, General},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {kein abstract},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2019-29&engl=1}
}
@inproceedings {INPROC-2019-28,
   author = {Claes Neuefeind and Philip Schildkamp and Brigitte Mathiak and Lukas Harzenetter and Johanna Barzen and Uwe Breitenb{\"u}cher and Frank Leymann},
   title = {{Technologienutzung im Kontext Digitaler Editionen. Eine Landschaftsvermessung}},
   booktitle = {DHd 2019 Digital Humanities: multimedial \& multimodal. Konferenzabstracts},
   publisher = {Zenodo},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--1},
   type = {Conference Paper},
   month = {March},
   year = {2019},
   language = {German},
   cr-category = {A.0 General Literature, General},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {kein abstract},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2019-28&engl=1}
}
@inproceedings {INPROC-2019-24,
   author = {Frank Leymann and Johanna Barzen and Michael Falkenthal},
   title = {{Towards a Platform for Sharing Quantum Software}},
   booktitle = {Proceedings of the 13th Advanced Summer School on Service Oriented Computing (2019)},
   publisher = {IBM Research Division},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {IBM Technical Report (RC25685)},
   pages = {70--74},
   type = {Conference Paper},
   month = {September},
   year = {2019},
   keywords = {Quantum computing; software engineering; middleware; platforms; cloud computing},
   language = {English},
   cr-category = {D.2.0 Software Engineering General,     C.5.0 Computer System Implementation, General},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Quantum computers solving real-world problems are expected to become general available within the next few years. But software for quantum computers require very different skills compared to creating software for traditional computers or networks. Thus, a community-driven approach to creating software for quantum computers will foster a wide-spread use of this innovative technology. Also, a platform for quantum software may provide a business model for several user groups.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2019-24&engl=1}
}
@inproceedings {INPROC-2019-13,
   author = {K{\'a}lm{\'a}n K{\'e}pes and Uwe Breitenb{\"u}cher and Frank Leymann},
   title = {{Situation-Aware Management of Cyber-Physical Systems}},
   booktitle = {Proceedings of the 9th International Conference on Cloud Computing and Services Science},
   editor = {SciTePress},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {551--560},
   type = {Conference Paper},
   month = {May},
   year = {2019},
   isbn = {978-989-758-365-0},
   isbn = {10.5220/0007799505510560},
   language = {English},
   cr-category = {D.2.9 Software Engineering Management},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The current trend of connecting the physical world with the so-called cyber world resulted in paradigms such as the Internet of Things or the more general paradigm of Cyber-Physical Systems. The wide range of domains applicable results in a heterogeneous landscape of software and hardware solutions. To benefit of the paradigm, developers must be able to integrate different solutions from a range of different domains. However, these systems must therefore be able to change components, configurations and environments, hence, be adaptable at runtime. We present an approach that is based on the combination of Situation-Aware Adaptation concepts and Deployment Models. The general idea is to start processes that can change application structure and configuration when a certain situation in the context of applications occur. We validated the technical feasibility of our approach by a prototypical implementation based on a Smart Home scenario.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2019-13&engl=1}
}
@inproceedings {INPROC-2019-11,
   author = {Karoline Saatkamp and Uwe Breitenb{\"u}cher and Michael Falkenthal and Lukas Harzenetter and Frank Leymann},
   title = {{An Approach to Determine \& Apply Solutions to Solve Detected Problems in Restructured Deployment Models Using First-Order Logic}},
   booktitle = {Proceedings of the 9th International Conference on Cloud Computing and Services Science (CLOSER 2019)},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {495--506},
   type = {Conference Paper},
   month = {May},
   year = {2019},
   isbn = {978-989-758-365-0},
   doi = {10.5220/0007763204950506},
   keywords = {deployment model; pattern; logic programming; pattern-based solution; model adaptation; TOSCA},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     D.2.2 Software Engineering Design Tools and Techniques,     D.2.12 Software Engineering Interoperability,     K.6 Management of Computing and Information Systems},
   ee = {http://closer.scitevents.org/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {New paradigms such as edge computing opened up new opportunities for distributing applications to meet use-case-specific requirements. For automating the deployment of applications, deployment models can be created that describe the application structure with its components and their relations. However, the distribution is often not known in advance and, thus, deployment models have to be restructured. This can result in problems that have not existed before, e.g., components previously deployed in the same network were distributed, but security mechanisms are missing. Architecture patterns can be used to detect such problems, however, patterns describe only generic technology-independent solutions, which cannot automatically be applied to applications. Several concrete technologies exist that implements the pattern. Which solutions are applicable to a particular application is determined by, e.g., its hosting environment or used communication protocol. However, the manual effort to determine and implement appropriate solutions is immense. In this work, we present an approach to automate (i) the determination of solutions for an application using first-order logic and (ii) the adaptation of its deployment model accordingly. To validate the practical feasibility, we present a prototype using the cloud standard TOSCA and the logic programming language PROLOG.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2019-11&engl=1}
}
@inproceedings {INPROC-2019-05,
   author = {Frank Leymann},
   title = {{Towards a Pattern Language for Quantum Algorithms}},
   booktitle = {First International Workshop, QTOP 2019, Munich, Germany, March 18, 2019, Proceedings},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {April},
   year = {2019},
   isbn = {978-3-030-14081-6},
   language = {German},
   cr-category = {D.2.11 Software Engineering Software Architectures},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Creating quantum algorithms is a difficult task, especially for computer scientist not used to quantum computing. But quantum algorithms often use similar elements. Thus, these elements provide proven solutions to recurring problems, i.e. a pattern language. Sketching such a language is a step towards establishing a software engineering discipline of quantum algorithms.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2019-05&engl=1}
}
@inproceedings {INPROC-2018-56,
   author = {Ulrich Odefey and Felix Baumann and Gerd Gr{\"u}nert and Sebastian Hudert and Michael Zimmermann and Michael Falkenthal and Frank Leymann},
   title = {{Manufacturing Smart Services for automotive production lines}},
   booktitle = {18. Internationales Stuttgarter Symposium},
   editor = {Michael Bargende and Hans-Christian Reuss and Jochen Wiedemann},
   publisher = {Springer Fachmedien},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {813--825},
   type = {Conference Paper},
   month = {May},
   year = {2018},
   isbn = {978-3-658-21194-3},
   language = {English},
   cr-category = {K.6 Management of Computing and Information Systems,     D.2.11 Software Engineering Software Architectures,     D.2.13 Software Engineering Reusable Software},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The intelligent exploitation of sensor data and order parameters from modern production systems is one of the biggest challenges in the context of Industry4.0. Currently, data from single machines are processed individually and not integrated with upstream or downstream processes. This case is prevalent in automotive assembly lines. Here, numerous machining tools from different vendors prohibit a smooth collaboration. However, only the aggregation of the entirety of available data sources permits a comprehensive and intelligent analysis and optimization of production lines. This approach leads to the regulation and behavior prediction of single components and finally of whole production systems. Such an intelligent assessment can be realized by Smart Services which are self-contained application containers allowing for efficient data analytics in modern production lines. The SePiA.Pro project develops and investigates a self-describing and secure packaging format for Smart Services facilitating their automatic provisioning. The project implements an open, standard- and cloud-based platform consisting of a modelling environment for Smart Services; a repository for the exchange of Smart Services; and a provisioning engine for automated deployment of Smart Services. Said platform opens up modern data analytics capabilities for anyone, as both customers and suppliers of analytics services. Use cases from automotive manufacturing demonstrate the value of the developed solution.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-56&engl=1}
}
@inproceedings {INPROC-2018-49,
   author = {Lukas Harzenetter and Uwe Breitenb{\"u}cher and Michael Falkenthal and Jasmin Guth and Christoph Krieger and Frank Leymann},
   title = {{Pattern-based Deployment Models and Their Automatic Execution}},
   booktitle = {11th IEEE/ACM International Conference on Utility and Cloud Computing (UCC 2018)},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {41--52},
   type = {Conference Paper},
   month = {December},
   year = {2018},
   doi = {10.1109/UCC.2018.00013},
   language = {English},
   cr-category = {D.2.9 Software Engineering Management},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The automated deployment of cloud applications is of vital importance. Therefore, several deployment automation technologies have been developed that enable automatically deploying applications by processing so-called deployment models, which describe the components and relationships an application consists of. However, the creation of such deployment models requires considerable expertise about the technologies and cloud providers used—especially for the technical realization of conceptual architectural decisions. Moreover, deployment models have to be adapted manually if architectural decisions change or technologies need to be replaced, which is time-consuming, error-prone, and requires even more expertise. In this paper, we tackle this issue. We introduce a meta-model for Pattern-based Deployment Models, which enables using cloud patterns as generic, vendor-, and technology-agnostic modeling elements directly in deployment models. Thus, instead of specifying concrete technologies, providers, and their configurations, our approach enables modeling only the abstract concepts represented by patterns that must be adhered to during the deployment. Moreover, we present how these models can be automatically refined to executable deployment models. To validate the practical feasibility of our approach, we present a prototype based on the TOSCA standard and a case study.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-49&engl=1}
}
@inproceedings {INPROC-2018-48,
   author = {Michael Wurster and Uwe Breitenb{\"u}cher and K{\'a}lm{\'a}n K{\'e}pes and Frank Leymann and Vladimir Yussupov},
   title = {{Modeling and Automated Deployment of Serverless Applications using TOSCA}},
   booktitle = {Proceedings of the IEEE 11th International Conference on Service-Oriented Computing and Applications (SOCA)},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {73--80},
   type = {Conference Paper},
   month = {November},
   year = {2018},
   doi = {10.1109/SOCA.2018.00017},
   keywords = {Serverless; Multi-Cloud; Modeling; Automated Deployment; TOSCA},
   language = {English},
   cr-category = {D.2.2 Software Engineering Design Tools and Techniques,     D.2.9 Software Engineering Management,     D.2.11 Software Engineering Software Architectures},
   contact = {Michael Wurster michael.wurster@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The serverless computing paradigm brings multiple benefits to application developers who are interested in consuming computing resources as services without the need to manage physical capacities or limits. There are several deployment technologies and languages available suitable for deploying applications to a single cloud provider. However, for multi-cloud application deployments, multiple technologies have to be used and orchestrated. In addition, the event-driven nature of serverless computing imposes further requirements on modeling such application structures in order to automate their deployment. In this paper, we tackle these issues by introducing an event-driven deployment modeling approach using the standard Topology and Orchestration Specification for Cloud Applications (TOSCA) that fully employs the suggested standard lifecycle to provision and manage multi-cloud serverless applications. To show the feasibility of our approach, we extended the existing TOSCA-based ecosystem OpenTOSCA.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-48&engl=1}
}
@inproceedings {INPROC-2018-47,
   author = {Michael Falkenthal and Uwe Breitenb{\"u}cher and Frank Leymann},
   title = {{The Nature of Pattern Languages}},
   booktitle = {Pursuit of Pattern Languages for Societal Change},
   publisher = {tredition},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {130--150},
   type = {Conference Paper},
   month = {October},
   year = {2018},
   keywords = {Pattern Language; Pattern Repository; Pattern Application; Pattern Ontology; Pattern Formalization; Pattern Language Composition; Pattern Graph},
   language = {English},
   cr-category = {C.0 Computer Systems Organization, General,     D.2.2 Software Engineering Design Tools and Techniques,     D.2.3 Software Engineering Coding Tools and Techniques,     D.2.7 Software Engineering Distribution, Maintenance, and Enhancement},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Patterns and pattern languages have emerged in many disciplines to capture deep domain expertise and knowledge about solving frequently recurring problems by proven solutions. Thereby, patterns capture the essence of many implementations along with descriptions about how to apply them in combination with other patterns, which manifests in pattern languages. Although pattern languages are a powerful means to preserve and reuse expertise, a clear definition is missing about what a pattern language actually is. Pattern languages are primarily described as being networks of patterns which does not provide a clear and unambiguous foundation to reveal their nature. This lack of rational about the structure behind pattern languages hinders reasoning about them to grasp what connections between patterns are and how the interplay of patterns from different pattern languages can be authored and managed. Therefore, we present a formal notion of pattern languages as node-colored and edge-weighted directed multigraphs. We show how this model can be used to sharpen Alexander's idea of pattern languages. Thereby, we illustrate how pattern languages can be authored and adapted to establish living networks of patterns. We further introduce that patterns are specific renderings of such a graph depending on actual problems and use cases at hand. This manifests in the fact that our graph concept extracts relationships between patterns from the patterns themselves, which enables easily adaptable networks of patterns. This can be leveraged as the formal meta-model for developing tool support for authoring and sharing pattern languages among communities via IT-based systems.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-47&engl=1}
}
@inproceedings {INPROC-2018-44,
   author = {Michael Zimmermann and Uwe Breitenb{\"u}cher and Jasmin Guth and Sibylle Hermann and Frank Leymann and Karoline Saatkamp},
   title = {{Towards Deployable Research Object Archives Based on TOSCA}},
   booktitle = {Papers From the 12th Advanced Summer School of Service-Oriented Computing (SummerSoC 2018)},
   publisher = {IBM Research Division},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {31--42},
   type = {Conference Paper},
   month = {October},
   year = {2018},
   keywords = {Research Object; Reusability; Reproducibility; Deployment Model; TOSCA},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     D.2.7 Software Engineering Distribution, Maintenance, and Enhancement,     H.3.7 Digital Libraries},
   ee = {https://www.2018.summersoc.eu/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In science, reproducibility means that a scientific experiment can be repeated by another scientist with the same result. This is of particular importance to verify the results as well as to show the usefulness and reusability for further research. However, the exclusive publication of the research results in a scientific journal is usually not sufficient. In addition to research results, also research data as well as research software need to be published and made public available in order to enable researcher to gain new insights and thus advance research. However, the reproducibility and reusability of research data and research software typically is hindered by several barriers. Therefore, this work intends to first provide an overview of the current situation and issues in this particular topic and furthermore sketch our vision of standards-based Research Object Archives containing scientific publications, software, data, metadata and licenses in order to tackle the existing problems.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-44&engl=1}
}
@inproceedings {INPROC-2018-43,
   author = {Ghareeb Falazi and Uwe Breitenb{\"u}cher and Michael Falkenthal and Lukas Harzenetter and Frank Leymann and Vladimir Yussupov},
   title = {{Blockchain-based Collaborative Development of Application Deployment Models}},
   booktitle = {On the Move to Meaningful Internet Systems. OTM 2018 Conferences (CoopIS 2018)},
   publisher = {Springer International Publishing AG},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science},
   volume = {11229},
   pages = {40--60},
   type = {Conference Paper},
   month = {October},
   year = {2018},
   isbn = {978-3-030-02610-3},
   doi = {10.1007/978-3-030-02610-3_3},
   keywords = {Blockchains; Distributed Storage System; Collaborative Modeling; Declarative Software Deployment Models},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     H.4.1 Office Automation},
   contact = {Ghareeb Falazi: ghareeb.falazi@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The automation of application deployment is vital today as manually deploying applications is too slow and error prone. For this reason, various deployment automation technologies have been developed that process deployment models to automatically deploy applications. However, in many scenarios, these deployment models have to be created in collaborative processes involving multiple participants that belong to independent organizations. For example, in data analytics scenarios, often external data scientists develop algorithms to process business-critical data of a company, while IT experts specify the technical infrastructure to deploy algorithms and data. However, as these deployment modeling processes are typically highly iterative and as the participating organizations may have competing interests, the degree of trust they have in each other is limited. Thus, without a guarantee of accountability, iterative collaborative deployment modeling is not possible in business critical domains. In this paper, we propose a decentralized approach that aims at achieving accountability in collaborative deployment modeling processes by utilizing public blockchains to store intermediate states of the collaborative deployment model in a way that guarantees its integrity and allows obtaining the history of changes it went through. The approach utilizes the same blockchain to establish the identity and authenticity of all participants of the process. We validate our approach by providing an architecture and a prototypical implementation of a blockchain-based deployment modeling environment based on the TOSCA standard.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-43&engl=1}
}
@inproceedings {INPROC-2018-42,
   author = {Christoph Krieger and Uwe Breitenb{\"u}cher and K{\'a}lm{\'a}n K{\'e}pes and Frank Leymann},
   title = {{An Approach to Automatically Check the Compliance of Declarative Deployment Models}},
   booktitle = {Papers from the 12th Advanced Summer School on Service-Oriented Computing (SummerSoC 2018)},
   publisher = {IBM Research Division},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {76--89},
   type = {Conference Paper},
   month = {October},
   year = {2018},
   keywords = {Cloud Computing; Compliance; Deployment Modeling},
   language = {English},
   cr-category = {D.2.2 Software Engineering Design Tools and Techniques,     D.2.3 Software Engineering Coding Tools and Techniques},
   contact = {Christoph Krieger christoph.krieger@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The automation of application deployment has evolved into one of the most important issues in modern enterprise IT. Therefore, many deployment systems have been developed that process deployment models for automating the installation of systems. Creating such deployment models becomes more and more complex as compliance plays an increasingly important role. Not only external laws and regulations must be considered, but also a company’s internal requirements must be fulfilled. However, this is a very complex challenge for the modelers as they require a firm knowledge of all the compliance rules that must be observed. As a result, this often leads to deployment models that violate compliance rules due to manual modeling mistakes or because of unawareness. In this paper, we introduce an approach that enables modeling of reusable Deployment Compliance Rules that can be executed automatically to check such regulations in declarative deployment models at design time. We validate our approach with a prototype based on the TOSCA standard and the OpenTOSCA ecosystem.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-42&engl=1}
}
@inproceedings {INPROC-2018-41,
   author = {Michael Wurster and Uwe Breitenb{\"u}cher and Oliver Kopp and Frank Leymann},
   title = {{Modeling and Automated Execution of Application Deployment Tests}},
   booktitle = {Proceedings of the IEEE 22nd International Enterprise Distributed Object Computing Conference (EDOC)},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {171--180},
   type = {Conference Paper},
   month = {October},
   year = {2018},
   doi = {10.1109/EDOC.2018.00030},
   keywords = {Testing; Declarative Application Deployment; Test Automation; Model-based Testing; TOSCA},
   language = {English},
   cr-category = {D.2.5 Software Engineering Testing and Debugging,     D.2.9 Software Engineering Management},
   contact = {Michael Wurster michael.wurster@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In recent years, many deployment systems have been developed that process deployment models to automatically provision applications. The main objective of these systems is to shorten delivery times and to ensure a proper execution of the deployment process. However, these systems mainly focus on the correct technical execution of the deployment, but do not check whether the deployed application is working properly. Especially in DevOps scenarios where applications are modified frequently, this can quickly lead to broken deployments, for example, if a wrong component version was specified in the deployment model that has not been adapted to a new database schema. Ironically, even hardly noticeable errors in deployment models quickly result in technically successful deployments, which do not work at all. In this paper, we tackle these issues. We present a modeling concept that enables developers to define deployment tests directly along with the deployment model. These tests are then automatically run by a runtime after deployment to verify that the application is working properly. To validate the technical feasibility of the approach, we applied the concept to TOSCA and extended an existing open source TOSCA runtime.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-41&engl=1}
}
@inproceedings {INPROC-2018-40,
   author = {Michael Hahn and Uwe Breitenb{\"u}cher and Frank Leymann and Michael Wurster and Vladimir Yussupov},
   title = {{Modeling Data Transformations in Data-Aware Service Choreographies}},
   booktitle = {Proceedings of the IEEE 22nd International Enterprise Distributed Object Computing Conference (EDOC)},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {28--34},
   type = {Conference Paper},
   month = {October},
   year = {2018},
   doi = {10.1109/EDOC.2018.00014},
   language = {English},
   cr-category = {H.4.1 Office Automation,     C.2.4 Distributed Systems},
   contact = {Michael Hahn: michael.hahn@iaas-uni.stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The importance of data is steadily increasing in the domain of business process management due to recent advances in data science, IoT, and Big Data. To reflect this paradigm shift towards data-awareness in service choreographies, we introduced the notion of data-aware choreographies based on concepts for Transparent Data Exchange (TraDE) in our previous works. The goal is to simplify the modeling of business-relevant data and its exchange in choreography models while increasing their run time flexibility. To further improve and simplify the modeling of data-related aspects in service choreographies, in this paper, we focus on the extension of our TraDE concepts to support the modeling of data transformations in service choreographies. Such data transformation capabilities are of dire need to mediate between different data formats, structures and representations of the collaborating participants within service choreographies. Therefore, the paper presents a modeling extension as means for specifying and executing heterogeneous data transformations in service choreographies based on our TraDE concepts.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-40&engl=1}
}
@inproceedings {INPROC-2018-39,
   author = {Michael Hahn and Uwe Breitenb{\"u}cher and Frank Leymann and Vladimir Yussupov},
   title = {{Transparent Execution of Data Transformations in Data-Aware Service Choreographies}},
   booktitle = {On the Move to Meaningful Internet Systems. OTM 2018 Conferences (CoopIS 2018)},
   publisher = {Springer International Publishing AG},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science},
   volume = {11230},
   pages = {117--137},
   type = {Conference Paper},
   month = {October},
   year = {2018},
   isbn = {978-3-030-02671-4},
   doi = {10.1007/978-3-030-02671-4_7},
   keywords = {Data-aware Choreographies; Data Transformation; TraDE},
   language = {English},
   cr-category = {H.4.1 Office Automation,     C.2.4 Distributed Systems},
   contact = {Michael Hahn: michael.hahn@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Due to recent advances in data science, IoT, and Big Data, the importance of data is steadily increasing in the domain of business process management. Service choreographies provide means to model complex conversations between collaborating parties from a global viewpoint. However, the involved parties often rely on their own data formats. To still enable the interaction between them within choreographies, the underlying business data has to be transformed between the different data formats. The state-of-the-art in modeling such data transformations as additional tasks in choreography models is error-prone, time consuming and pollutes the models with functionality that is not relevant from a business perspective but technically required. As a first step to tackle these issues, we introduced in previous works a data transformation modeling extension for defining data transformations on the level of choreography models independent of their control flow as well as concrete technologies or tools. However, this modeling extension is not executable yet. Therefore, this paper presents an approach and a supporting integration middleware which enable to provide and execute data transformation implementations based on various technologies or tools in a generic and technology-independent manner to realize an end-to-end support for modeling and execution of data transformations in service choreographies.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-39&engl=1}
}
@inproceedings {INPROC-2018-38,
   author = {Andreas Liebing and Lutz Ashauer and Uwe Breitenb{\"u}cher and Thomas G{\"u}nther and Michael Hahn and K{\'a}lm{\'a}n K{\'e}pes and Oliver Kopp and Frank Leymann and Bernhard Mitschang and Ana C. Franco da Silva and Ronald Steinke},
   title = {{The SmartOrchestra Platform: A Configurable Smart Service Platform for IoT Systems}},
   booktitle = {Papers from the 12th Advanced Summer School on Service-Oriented Computing (SummerSoC 2018)},
   publisher = {IBM Research Division},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {14--21},
   type = {Conference Paper},
   month = {October},
   year = {2018},
   keywords = {SmartOrchestra Platform; Smart Services; Cyber-Physical Systems; Internet of Things},
   language = {English},
   cr-category = {K.6 Management of Computing and Information Systems,     D.2.7 Software Engineering Distribution, Maintenance, and Enhancement,     D.2.12 Software Engineering Interoperability},
   ee = {https://www.2018.summersoc.eu/},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The Internet of Things is growing rapidly while still missing a universal operat-ing and management platform for multiple diverse use cases. Such a platform should provide all necessary functionalities and the underlying infrastructure for the setup, execution and composition of Smart Services. The concept of Smart Services enables the connection and integration of cyber-physical systems (CPS) and technologies (i.e., sensors and actuators) with business-related applications and services. Therefore, the SmartOrchestra Platform provides an open and standards-based service platform for the utilization of public administrative and business-related Smart Services. It combines the features of an operating plat-form, a marketplace, a broker, and a notary for a cloud-based operation of Smart Services. Thus, users of cyber-physical systems are free to choose their control applications, no matter what device they are using (e.g., smartphone, tablet or personal computer) and they also become independent of the manufacturers’ software. This will enable new business opportunities for different stakeholders in the market and allows flexibly composing Smart Services.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-38&engl=1}
}
@inproceedings {INPROC-2018-37,
   author = {Jasmin Guth and Frank Leymann},
   title = {{Towards Pattern-based Rewrite and Refinement of Application Architectures}},
   booktitle = {Papers From the 12th Advanced Summer School on Service-Oriented Computing (SummerSOC'18)},
   publisher = {IBM Research Division},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {90--100},
   type = {Conference Paper},
   month = {October},
   year = {2018},
   keywords = {Application Architectures; Patterns; Solution Paths; Rewrite; Refinement; Graph Transformation},
   language = {English},
   cr-category = {C.0 Computer Systems Organization, General,     C.2.4 Distributed Systems,     D.2.1 Software Engineering Requirements/Specifications,     K.6 Management of Computing and Information Systems},
   ee = {https://www.2018.summersoc.eu},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-37&engl=1}
}
@inproceedings {INPROC-2018-36,
   author = {Vladimir Yussupov and Michael Falkenthal and Oliver Kopp and Frank Leymann and Michael Zimmermann},
   title = {{Secure Collaborative Development of Cloud Application Deployment Models}},
   booktitle = {Proceedings of The Twelfth International Conference on Emerging Security Information, Systems and Technologies (SECURWARE 2018)},
   editor = {Georg Yee and Stefan Rass and Stefan Schauer and Martin Latzenhofer},
   publisher = {Xpert Publishing Services},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {48--57},
   type = {Conference Paper},
   month = {September},
   year = {2018},
   isbn = {9781612086613},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures,     D.4.6 Operating Systems Security and Protection},
   contact = {Vladimir Yussupov yussupov@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-36&engl=1}
}
@inproceedings {INPROC-2018-35,
   author = {Claes Neuefeind and Lukas Harzenetter and Philip Schildkamp and Uwe Breitenb{\"u}cher and Brigitte Mathiak and Johanna Barzen and Frank Leymann},
   title = {{The SustainLife Project - Living Systems in Digital Humanities}},
   booktitle = {Papers From the 12th Advanced Summer School of Service-Oriented Computing (SummerSOC 2018)},
   publisher = {IBM Research Division},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {101--112},
   type = {Conference Paper},
   month = {October},
   year = {2018},
   keywords = {Living Systems; Sustainability; Research Software},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     D.2.7 Software Engineering Distribution, Maintenance, and Enhancement,     K.6 Management of Computing and Information Systems},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In the arts and humanities, research applications play a central role in securing and presenting digital results. However, due to their steadily increasing number and their heterogeneity, it is difficult to ensure the sustainability and durability of this kind of living systems from an organizational point of view. This paper describes a project for the preservation of specialized web-based research applications in the humanities. The SustainLife project investigates to what extent methods and technologies of professional cloud deployment and provisioning strategies can be applied to problems of long-term availability of research software as they are omnipresent in humanities data centers such as the Data Center for the Humanities (DCH) at the University of Cologne. Technological basis of the project is the OASIS standard TOSCA and the Open Source implementation OpenTOSCA, respectively, which was developed at the Institute for Architecture of Application Systems (IAAS) at the University of Stuttgart. In the course of the project selected use cases from the field of Digital Humanities (DH) will be modeled in TOSCA to be able to automatically deploy them upon request at any time. The TOSCA standard enables a portable description of the modeled systems independent of specific providers to facilitate their long-term availability. The aim is to provide system components described in the use cases in a component library, as well as in the form of TOSCAcompliant application templates to make them available for reuse in other DH projects.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-35&engl=1}
}
@inproceedings {INPROC-2018-33,
   author = {Karoline Saatkamp and Uwe Breitenb{\"u}cher and Oliver Kopp and Frank Leymann},
   title = {{Application Scenarios for Automated Problem Detection in TOSCA Topologies by Formalized Patterns}},
   booktitle = {Papers From the 12th Advanced Summer School of Service-Oriented Computing (SummerSOC 2018)},
   publisher = {IBM Research Division},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {43--53},
   type = {Conference Paper},
   month = {October},
   year = {2018},
   keywords = {Cloud Computing Patterns; Formalization; Prolog; TOSCA},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     D.2.7 Software Engineering Distribution, Maintenance, and Enhancement,     K.6 Management of Computing and Information Systems},
   ee = {https://www.2018.summersoc.eu/},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-33&engl=1}
}
@inproceedings {INPROC-2018-32,
   author = {Michael Zimmermann and Uwe Breitenb{\"u}cher and Christoph Krieger and Frank Leymann},
   title = {{Deployment Enforcement Rules for TOSCA-based Applications}},
   booktitle = {Proceedings of The Twelfth International Conference on Emerging Security Information, Systems and Technologies (SECURWARE 2018)},
   editor = {Georg Yee and Stefan Rass and Stefan Schauer and Martin Latzenhofer},
   publisher = {Xpert Publishing Services},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {114--121},
   type = {Conference Paper},
   month = {September},
   year = {2018},
   isbn = {9781612086613},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures,     D.4.6 Operating Systems Security and Protection},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In the context of Industry 4.0, gathering sensor dataand using data analysis software can lead to actionable insights,for example, enabling predictive maintenance. Since developingthese data analysis software requires some special expert knowl-edge, often external data scientist are charged for that. However,often the data to be analyzed is of vital importance and thus,must not leave the company. Therefore, applications developedand modeled as deployment models by third-parties have tobe enforced to be executed in the local company’s network.However, manually adapting a lot of these deployment modelsin order to meet the company’s requirements is cumbersome,time consuming and error-prone. Furthermore, some kind ofenforcement mechanism is required to really ensure that thesedata security and privacy requirements are fulfilled. Thus, in thispaper, we present an approach considering these issues duringthe deployment time of the application. The presented approachis based on the Topology and Orchestration Specification forCloud Applications (TOSCA), an OASIS standard enabling thedescription of cloud applications as well as their deployment. Theapproach enables the specification as well as the enforcement ofreoccurring and generic requirements and restrictions of TOSCA-based declarative deployment models, without the need to adaptor modify these deployment models. The practical feasibilityof the presented approach is validated by extending our open-source prototype OpenTOSCA, which provides a modeling tool,a TOSCA Runtime, as well as a self-service portal for TOSCA.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-32&engl=1}
}
@inproceedings {INPROC-2018-31,
   author = {Michael Zimmermann and Uwe Breitenb{\"u}cher and Frank Leymann},
   title = {{A Method and Programming Model for Developing Interacting Cloud Applications Based on the TOSCA Standard}},
   booktitle = {Enterprise Information Systems},
   publisher = {Springer International Publishing},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Business Information Processing},
   volume = {321},
   pages = {265--290},
   type = {Conference Paper},
   month = {June},
   year = {2018},
   doi = {10.1007/978-3-319-93375-7},
   language = {English},
   cr-category = {D.2.3 Software Engineering Coding Tools and Techniques,     D.2.11 Software Engineering Software Architectures},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Many cloud applications are composed of several interacting components and services. The communication between these components can be enabled, for example, by using standards such as WSDL and the workflow technology. In order to wire these components several endpoints must be exchanged, e.g., the IP addresses of deployed services. However, this exchange of endpoint information is highly dependent on the (i) middleware technologies, (ii) programming languages, and (iii) deployment technology used in a concrete scenario and, thus, increases the complexity of implementing such interacting applications. In this paper, we propose a programming model that eases the implementation of interacting components of automatically deployed TOSCA-based applications. Furthermore, we present a method following our programming model, which describes how such a cloud application can be systematically modeled, developed, and automatically deployed based on the TOSCA standard and how code generation capabilities can be utilized for this. The practical feasibility of the presented approach is validated by a system architecture and a prototypical implementation based on the OpenTOSCA ecosystem. This work is an extension of our previous research we presented at the International Conference on Enterprise Information Systems (ICEIS).},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-31&engl=1}
}
@inproceedings {INPROC-2018-27,
   author = {Claes Neuefeind and Philip Schildkamp and Brigitte Mathiak and Johanna Barzen and Uwe Breitenb{\"u}cher and Lukas Harzenetter and Frank Leymann},
   title = {{Lebende Systeme in den Digital Humanities - das Projekt SustainLife}},
   booktitle = {20. Workshop Software-Reengineering und -Evolution (WSRE 2018) der GI-Fachgruppe Software-Reengineering, Bad-Honnef, 02.-04. Mai 2018, Proceedings},
   publisher = {GI Gesellschaft f{\"u}r Informatik e.V. (GI)},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {37--38},
   type = {Conference Paper},
   month = {May},
   year = {2018},
   language = {German},
   cr-category = {C.0 Computer Systems Organization, General},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Der Beitrag beschreibt einen L{\"o}sungsansatz f{\"u}r den Erhalt spezialisierter, webbasierter Forschungsanwendungen in den Geisteswissenschaften. Die Modellierung auf Grundlage des TOSCA-Standards erlaubt eine portable Beschreibung der Systeme unabh{\"a}ngig von konkreten Anbietern, um deren langfristige Verfugbarkeit zu erm{\"o}glichen. Anhand konkreter Usecases aus dem Bereich der Digital Humanities (DH) werden im SustainLife-Projekt Schl{\"a}sselkomponenten identifiziert und Anwendungsvorlagen erstellt, die uber die OpenTosca-Umgebung f{\"u}r die Modellierung von DH-Anwendungen zur Verf{\"u}gung gestellt werden. Die im Projekt modellierten Usecases werden zudem als Praxisbeispiele zur Verf{\"u}gung gestellt.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-27&engl=1}
}
@inproceedings {INPROC-2018-25,
   author = {Karoline Saatkamp and Uwe Breitenb{\"u}cher and K{\'a}lm{\'a}n K{\'e}pes and Frank Leymann and Michael Zimmermann},
   title = {{OpenTOSCA Injector: Vertical and Horizontal Topology Model Injection}},
   booktitle = {Service-Oriented Computing - ICSOC 2017 Workshop},
   publisher = {Springer International Publishing},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {LNCS},
   volume = {10797},
   pages = {379--383},
   type = {Demonstration},
   month = {January},
   year = {2018},
   isbn = {10.1007/978-3-319-91764-1},
   keywords = {TOSCA; Deployment Model; Completion Automation},
   language = {English},
   cr-category = {D.2.2 Software Engineering Design Tools and Techniques,     D.2.9 Software Engineering Management},
   ee = {http://www.icsoc.spilab.es/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-25&engl=1}
}
@inproceedings {INPROC-2018-20,
   author = {Sanjiva Weerawarana and Chathura Ekanayake and Srinath Perera and Frank Leymann},
   title = {{Bringing Middleware to Everyday Programmers with Ballerina}},
   booktitle = {Proceedings of the 16th International Conference on Business Process Management (BPM 2018), Sydney, Australia, September 9-14, 2018},
   publisher = {Springer, Cham},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science (LNCS)},
   type = {Conference Paper},
   month = {September},
   year = {2018},
   isbn = {978-3-319-98648-7},
   keywords = {Flow Languages; Middleware; Integration Technology},
   language = {English},
   cr-category = {D.2.3 Software Engineering Coding Tools and Techniques,     D.3.0 Programming Languages General},
   ee = {https://link.springer.com/chapter/10.1007/978-3-319-98648-7_2},
   contact = {Frank Leymann: frank.leymann@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Ballerina is a new language for solving integration problems. It is based on insights and best practices derived from languages like BPEL, BPMN, Go, and Java, but also cloud infrastructure systems like Kubernetes. Integration problems were traditionally addressed by dedicated middleware systems such as enterprise service buses, work ow systems and message brokers. However, such systems lack agility required by current integration scenarios, especially for cloud based deployments. This paper discusses how Ballerina solves this problem by bringing integration features into a general purpose programming language.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-20&engl=1}
}
@inproceedings {INPROC-2018-18,
   author = {Ana Cristina Franco da Silva and Pascal Hirmer and Uwe Breitenb{\"u}cher and Oliver Kopp and Bernhard Mitschang},
   title = {{TDLIoT: A Topic Description Language for the Internet of Things}},
   booktitle = {ICWE 2018: Web Engineering},
   editor = {Tommi Mikkonen and Ralf Klamma and Juan Hern{\'a}ndez},
   publisher = {Springer Berlin Heidelberg},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science (LNCS)},
   volume = {10845},
   pages = {333--348},
   type = {Conference Paper},
   month = {May},
   year = {2018},
   doi = {10.1007/978-3-319-91662-0_27},
   keywords = {Internet of Things; Publish-subscribe; Description Language},
   language = {English},
   cr-category = {K.6 Management of Computing and Information Systems,     D.2.12 Software Engineering Interoperability},
   ee = {https://link.springer.com/chapter/10.1007/978-3-319-91662-0_27},
   contact = {franco-da-silva@informatik.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-18&engl=1}
}
@inproceedings {INPROC-2018-13,
   author = {Felix W. Baumann and Ulrich Odefey and Sebastian Hudert and Michael Falkenthal and Uwe Breitenb{\"u}cher},
   title = {{Utilising the Tor Network for IoT Addressing and Connectivity}},
   booktitle = {Proceedings of the 8th International Conference on Cloud Computing and Services Science},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {27--34},
   type = {Conference Paper},
   month = {March},
   year = {2018},
   doi = {10.5220/0006591500270034},
   isbn = {978-989-758-295-0},
   keywords = {Tor Network; IoT Connectivity; Internet of Things; Addressing},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures,     D.2.12 Software Engineering Interoperability,     H.3.4 Information Storage and Retrieval Systems and Software},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {For Internet of Things (IoT) devices and cyber-physical systems (CPS), it is required to connect them securely and reliably to some form of cloud environment or computing entity for control, management and utilisation. The Internet is a suitable, standardized, and proven means for the connection of IoT devices in various scenarios. Connection over the Internet utilises existing protocols, standards, technologies and avoids investment in new, specialised concepts. Thereby, this connection requires a transparent addressing schema which is commonly TCP/IP, using domain names and IP addresses. However, in industrial, commercial and private networks, the addressability and connectability/connectivity is often limited by firewalls, proxies and router configurations utilising NAT. Thus, the present network configurations hinder the spread across different locations. Therefore, the method for connecting IoT devices in a client-server configuration proposed herein utilises the Tor (previously: The onion router/routing) network for addressing of and secured communication to IoT and CPS devices. It is an overlay protocol that was designed to allow for robust and anonymous communication. The benefit of this approach is to enable addressability and connectivity of IoT devices in firewalled and potentially unknown and changing network environments, thus allowing for IoT devices to be used reliably behind firewalls as long as outgoing communication is not blocked.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-13&engl=1}
}
@inproceedings {INPROC-2018-12,
   author = {Oliver Kopp and Uwe Breitenb{\"u}cher and Tamara M{\"u}ller},
   title = {{CloudRef - Towards Collaborative Reference Management in the Cloud}},
   booktitle = {Proceedings of the 10th Central European Workshop on Services and their Composition (ZEUS 2018)},
   editor = {Nico Herzberg and Christoph Hochreiner and Oliver Kopp and J{\"o}rg Lenhard},
   publisher = {CEUR-WS.org},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {CEUR Workshop Proceedings},
   volume = {2072},
   pages = {63--68},
   type = {Workshop Paper},
   month = {April},
   year = {2018},
   issn = {1613-0073},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://ceur-ws.org/Vol-2072/,     http://ceur-ws.org/Vol-2072/paper10.pdf},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-12&engl=1}
}
@inproceedings {INPROC-2018-11,
   author = {Oliver Kopp and Anita Armbruster and Olaf Zimmermann},
   title = {{Markdown Architectural Decision Records: Format and Tool Support}},
   booktitle = {Proceedings of the 10th Central European Workshop on Services and their Composition (ZEUS 2018)},
   editor = {Nico Herzberg and Christoph Hochreiner and Oliver Kopp and J{\"o}rg Lenhard},
   publisher = {CEUR-WS.org},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {CEUR Workshop Proceedings},
   volume = {2072},
   pages = {55--62},
   type = {Conference Paper},
   month = {April},
   year = {2018},
   issn = {1613-0073},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://ceur-ws.org/Vol-2072/,     http://ceur-ws.org/Vol-2072/paper9.pdf},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-11&engl=1}
}
@inproceedings {INPROC-2018-06,
   author = {K{\'a}lm{\'a}n K{\'e}pes and Uwe Breitenb{\"u}cher and Frank Leymann},
   title = {{Integrating IoT Devices Based on Automatically Generated Scale-Out Plans}},
   booktitle = {Proceedings of the 2017 IEEE 10th Conference on Service-Oriented Computing and Applications (SOCA 2017)},
   address = {Kanazawa, Japan},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Service-Oriented Computing and Applications (SOCA)},
   volume = {10},
   pages = {155--163},
   type = {Conference Paper},
   month = {January},
   year = {2018},
   doi = {10.1109/SOCA.2017.29},
   keywords = {Internet of Things; Software Deployment; Integration; TOSCA; Scaling},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures,     D.2.13 Software Engineering Reusable Software},
   ee = {http://conferences.computer.org/soca/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2018-06&engl=1}
}
@inproceedings {INPROC-2017-76,
   author = {Uwe Zdun and Elena Navarro and Frank Leymann},
   title = {{Ensuring and Assessing Architecture Conformance to Microservice Decomposition Patterns}},
   booktitle = {15th International Conference, ICSOC 2017, Malaga, Spain, November 13–16, 2017, Proceedings},
   publisher = {Springer International Publishing},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {411--429},
   type = {Conference Paper},
   month = {November},
   year = {2017},
   doi = {10.1007/978-3-319-69035-3_29},
   language = {English},
   cr-category = {D.2.9 Software Engineering Management},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Microservice-based software architecture design has been widely discussed, and best practices have been published as architecture design patterns. However, conformance to those patterns is hard to ensure and assess automatically, leading to problems such as architectural drift and erosion, especially in the context of continued software evolution or large-scale microservice systems. In addition, not much in the component and connector architecture models is specific (only) to the microservices approach, whereas other aspects really specific to that approach, such as independent deployment of microservices, are usually modeled in other views or not at all. We suggest a set of constraints to check and metrics to assess architecture conformance to microservice patterns. In comparison to expert judgment derived from the patterns, a subset of these constraints and metrics shows a good relative performance and potential for automation.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-76&engl=1}
}
@inproceedings {INPROC-2017-75,
   author = {Lukas Reinfurt and Uwe Breitenb{\"u}cher and Michael Falkenthal and Paul Fremantle and Frank Leymann},
   title = {{Internet of Things Security Patterns}},
   booktitle = {Proceedings of the 24th Conference on Pattern Languages of Programs (PLoP '17)},
   editor = {The Hillside Group},
   address = {Vancouver},
   publisher = {ACM},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--28},
   type = {Conference Paper},
   month = {October},
   year = {2017},
   isbn = {978-1-941652-06-0},
   keywords = {Internet of Things; Design Patterns; Cyber-Physical Systems; Security; Privacy},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     D.2.11 Software Engineering Software Architectures,     D.4.6 Operating Systems Security and Protection},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The Internet of Things (IoT) is growing, with new technologies, standards, devices, platforms, and applications being constantly developed. This has lead to a confusing solution landscape, which makes understanding the various options and choosing a path between them difficult. In order to help with this problem, we have collected IoT Patterns, which are textual descriptions of common problems and their abstract solutions based on repeatedly found real life examples. With this work, we add some security related IoT Patterns to complement the already existing catalog of security patterns that can be applied to IoT systems. The Trusted Communication Partner and Outbound-Only Connection patterns decrease the attack surface of devices. The Permission Control and Personal Zone Hub patterns give device owners control over what happens with their devices and data. The Whitelist and Blacklist patterns control access to and prevent abuse of resources.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-75&engl=1}
}
@inproceedings {INPROC-2017-74,
   author = {Frank Leymann and Uwe Breitenb{\"u}cher and Sebastian Wagner and Johannes Wettinger},
   title = {{Native Cloud Applications: Why Monolithic Virtualization Is Not Their Foundation}},
   booktitle = {Cloud Computing and Services Science},
   publisher = {Springer International Publishing},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {16--40},
   type = {Conference Paper},
   month = {July},
   year = {2017},
   isbn = {978-3-319-62594-2},
   language = {English},
   cr-category = {K.6 Management of Computing and Information Systems,     D.2.12 Software Engineering Interoperability},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Due to the current hype around cloud computing, the term `native cloud application' becomes increasingly popular. It suggests an application to fully benefit from all the advantages of cloud computing. Many users tend to consider their applications as cloud native if the application is just bundled as a monolithic virtual machine or container. Even though virtualization is fundamental for implementing the cloud computing paradigm, a virtualized application does not automatically cover all properties of a native cloud application. In this work, which is an extension of a previous paper, we propose a definition of a native cloud application by specifying the set of characteristic architectural properties, which a native cloud application has to provide. We demonstrate the importance of these properties by introducing a typical scenario from current practice that moves an application to the cloud. The identified properties and the scenario especially show why virtualization alone is insufficient to build native cloud applications. We also outline how native cloud applications respect the core principles of service-oriented architectures, which are currently hyped a lot in the form of microservice architectures. Finally, we discuss the management of native cloud applications using container orchestration approaches as well as the cloud standard TOSCA.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-74&engl=1}
}
@inproceedings {INPROC-2017-68,
   author = {Michael Wurster and Uwe Breitenb{\"u}cher and Michael Falkenthal and Frank Leymann},
   title = {{Developing, Deploying, and Operating Twelve-Factor Applications with TOSCA}},
   booktitle = {In Proceedings of the 19th International Conference on Information Integration and Web-based Applications \& Services, Salzburg, Austria, December 4-6, 2017},
   editor = {Maria Indrawan-Santiago and Ivan Luiz Salvadori and Matthias Steinbauer and Ismail Khalil and Gabriele Anderst-Kotsis},
   publisher = {ACM},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {519--525},
   type = {Conference Paper},
   month = {December},
   year = {2017},
   isbn = {10.1145/3151759.3151830},
   keywords = {Cloud Computing; Twelve-Factor App; TOSCA},
   language = {English},
   cr-category = {D.2.2 Software Engineering Design Tools and Techniques,     D.2.9 Software Engineering Management},
   ee = {http://www.iiwas.org/conferences/iiwas2017},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-68&engl=1}
}
@inproceedings {INPROC-2017-67,
   author = {Karoline Saatkamp and Uwe Breitenb{\"u}cher and Frank Leymann and Michael Wurster},
   title = {{Generic Driver Injection for Automated IoT Application Deployments}},
   booktitle = {Proceedings of the 19th International Conference on Information Integration and Web-based Applications \& Services; Salzburg, Austria, December 4-6, 2017},
   editor = {Maria Indrawan-Santiago and Ivan Luiz Salvadori and Matthias Steinbauer and Ismail Khalil and Gabriele Anderst-Kotsis},
   publisher = {ACM},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {320--329},
   type = {Conference Paper},
   month = {December},
   year = {2017},
   isbn = {10.1145/3151759.3151789},
   keywords = {IoT Application Deployment; Drivers; Programming Model; TOSCA},
   language = {English},
   cr-category = {D.2.2 Software Engineering Design Tools and Techniques,     D.2.13 Software Engineering Reusable Software},
   ee = {http://www.iiwas.org/conferences/iiwas2017/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-67&engl=1}
}
@inproceedings {INPROC-2017-65,
   author = {Uwe Breitenb{\"u}cher and K{\'a}lm{\'a}n K{\'e}pes and Frank Leymann and Michael Wurster},
   title = {{Declarative vs. Imperative: How to Model the Automated Deployment of IoT Applications?}},
   booktitle = {Proceedings of the 11th Advanced Summer School on Service Oriented Computing},
   publisher = {IBM Research Division},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {18--27},
   type = {Conference Paper},
   month = {November},
   year = {2017},
   keywords = {Deployment Modelling; Declarative; Imperative; TOSCA},
   language = {English},
   cr-category = {D.2.13 Software Engineering Reusable Software,     K.6 Management of Computing and Information Systems},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The Internet of Things (IoT) has become an increasingly important domain, which more and more requires application deployment automation as manual deployment is time-consuming, error-prone, and costly. However, the variety of available deployment automation systems also increases the complexity of selecting the most appropriate technology. In this paper, we discuss how the deployment of complex composite IoT applications can be automated and discuss the conceptual strengths and weaknesses of declarative and imperative deployment modelling.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-65&engl=1}
}
@inproceedings {INPROC-2017-64,
   author = {Lukas Reinfurt and Michael Falkenthal and Uwe Breitenb{\"u}cher and Frank Leymann},
   title = {{Applying IoT Patterns to Smart Factory Systems}},
   booktitle = {Proceedings of the 11th Advanced Summer School on Service Oriented Computing},
   publisher = {IBM Research Division},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--10},
   type = {Conference Paper},
   month = {November},
   year = {2017},
   keywords = {Internet of Things; Architecture; Patterns; Industry 4.0; Smart Factory; Industrial Internet},
   language = {English},
   cr-category = {D.2.13 Software Engineering Reusable Software,     K.6 Management of Computing and Information Systems},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Creating Internet of Things systems is a complex challenge as it involves both software and hardware, and because it touches on constrained devices and networks, storage, analytics, automation, and many other topics. This is further complicated by the large number of available technologies and the variety of different protocols and standards. To help with the ensuing confusion, we presented Internet of Things Patterns in several categories, such as device communication and management, energy supply types, and operation modes. These patterns describe abstract solutions to common problems and can be used to understand and design Internet of Things systems. In this paper, we show that these patterns can be applied to Smart Factory systems, which is one of the many domains where the Internet of Things is applicable.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-64&engl=1}
}
@inproceedings {INPROC-2017-63,
   author = {Michael Falkenthal and Felix W. Baumann and Gerd Gr{\"u}nert and Sebastian Hudert and Frank Leymann and Michael Zimmermann},
   title = {{Requirements and Enforcement Points for Policies in Industrial Data Sharing Scenarios}},
   booktitle = {Proceedings of the 11th Advanced Summer School on Service Oriented Computing},
   publisher = {IBM Research Division},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {28--40},
   type = {Conference Paper},
   month = {November},
   year = {2017},
   keywords = {Requirements; Policies; Data Aggregation; Industrial Data; Data Integration; Industry 4.0},
   language = {English},
   cr-category = {K.6 Management of Computing and Information Systems,     D.2.13 Software Engineering Reusable Software},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Industry 4.0 endeavors often integrate and analyze a multitude of data, such as data about machinery, production steps, and environmental conditions, in order to optimize manufacturing processes. Thereby, they aim to reveal information hidden in formerly isolated data silos via holistic analytics approaches. However, the integration of such data silos is often accompanied by challenges according legal regulations, organizational obstructions, and technical implementations, among others. Therefore, in this work we present a list of key challenges, which have to be commonly overcome in integration projects dealing with essential data from production processes. They can be used as a check list to address recurring challenges in future Industry 4.0 projects. Finally, we identify several plug-points in an abstract integration architecture, which have to be considered in concrete projects at hand to enforced the requirements.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-63&engl=1}
}
@inproceedings {INPROC-2017-60,
   author = {Felix W. Baumann and Ulrich Odefey and Sebastian Hudert and Michael Falkenthal and Michael Zimmermann},
   title = {{Cyber-physical System Control via Industrial Protocol OPC UA}},
   booktitle = {Proceedings of the Eleventh International Conference on Advanced Engineering Computing and Applications in Sciences (ADVCOMP 2017)},
   publisher = {Xpert Publishing Services},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {45--49},
   type = {Conference Paper},
   month = {November},
   year = {2017},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     C.3 Special-Purpose and Application-Based Systems,     H.3.4 Information Storage and Retrieval Systems and Software},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The integration of cyber-physical systems (CPS) is gaining more and more momentum due to the advent of Industry 4.0. Thereby, one of the main challenges is to facilitate the connection to arbitrary machinery in order to monitor and control these automatically. Such a control flexibilizes production processes by enabling quick adaptions of production steps. Therefore, in this work, a system is described that enables the control of a 3D printer via the industrial standardized Machine-to-Machine (M2M) communication protocol Open Platform Communications Unified Architecture (OPC UA). The system is implemented on the basis of a micro computing platform, in this case a Raspberry Pi 2, and utilizes open-source libraries and tools. The implementation creates a cyber-physical system, consisting of a 3D printer, its control system, sensor data acquisition systems and their respective digital representation. With this control system, the usage of consumer-centric 3D printers, such as Fused Deposition Modeling (FDM) printers, in enterprise-like scenarios is enabled. This abstract and universal control mechanism facilitates research in 3D printing control structures and industrial application.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-60&engl=1}
}
@inproceedings {INPROC-2017-59,
   author = {Lukas Reinfurt and Uwe Breitenb{\"u}cher and Michael Falkenthal and Frank Leymann and Andreas Riegg},
   title = {{Internet of Things Patterns for Device Bootstrapping and Registration}},
   booktitle = {Proceedings of the 22nd European Conference on Pattern Languages of Programs (EuroPLoP)},
   editor = {ACM},
   publisher = {ACM},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--27},
   type = {Conference Paper},
   month = {November},
   year = {2017},
   keywords = {Internet of Things; Device; Bootstrapping; Registration},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures,     C.2.4 Distributed Systems},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {All kinds of large and small organizations are trying to find their place in the Internet of Things (IoT) space and keep expanding the portfolio of connected devices, platforms, applications, and services. But for these components to be able to communicate with each other they first have to be made aware of other components, their capabilities, and possible communication paths. Depending on the number and distribution of the devices this can become a complicated task. Several solutions are available, but the large number of existing and developing standards and technologies make selecting the right one confusing at times. We collected proven solution descriptions to reoccurring problems in the form of patterns to help Internet of Things architects and developers understand, design, and build systems in this space. We present ten new patterns which deal with initializing communication. Five of these patterns are described in detail in this paper. The patterns FACTORY BOOTSTRAP, MEDIUM-BASED BOOTSTRAP, and REMOTE BOOTSTRAP are used to bring information for setting up communication onto the device. Devices can be registered using the AUTOMATIC CLIENT-DRIVEN REGISTRATION, AUTOMATIC SERVER-DRIVEN REGISTRATION, or MANUAL USER-DRIVEN REGISTRATION patterns. During this process, a SERVER-DRIVEN MODEL, PRE-DEFINED DEVICE-DRIVEN MODEL, or DEVICE-DRIVEN MODEL is stored in a DEVICE REGISTRY to digitally represent the device.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-59&engl=1}
}
@inproceedings {INPROC-2017-57,
   author = {Michael Zimmermann and Michael Falkenthal and Frank Leymann and Felix W. Baumann and Ulrich Odefey},
   title = {{Automating the Provisioning and Integration of Analytics Tools with Data Resources in Industrial Environments using OpenTOSCA}},
   booktitle = {Proceedings of the 2017 IEEE 21st International Enterprise Distributed Object Computing Conference Workshops and Demonstrations (EDOCW 2017)},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {3--7},
   type = {Workshop Paper},
   month = {October},
   year = {2017},
   doi = {10.1109/EDOCW.2017.10},
   language = {English},
   cr-category = {D.2.13 Software Engineering Reusable Software},
   ee = {http://edoc2017.ca/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The fourth industrial revolution is driven by the integration and analysis of a vast amount of diverse data. Thereby, data about production steps, overall manufacturing processes, and also supporting processes is gathered to enable holistic analysis approaches. These approaches promise to provide new insights and knowledge by revealing cost saving possibilities and also automated adjustments of production processes. However, such scenarios typically require analytics services and data integration stacks since algorithms have to be developed, executed and therefore be wired with the data to be processed. This leads to complex setups of overall analytics environments that have to be installed, configured and managed according to the needs of different analysis scenarios and setups. The manual execution of such installations is time-consuming and error-prone. Therefore, we demonstrate how the different components of such combined integration and analytics scenarios can be modelled in order to be reused in different settings, while enabling the fully automated provisioning of overall analytics stacks and services.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-57&engl=1}
}
@inproceedings {INPROC-2017-56,
   author = {Michael Zimmermann and Uwe Breitenb{\"u}cher and Michael Falkenthal and Frank Leymann and Karoline Saatkamp},
   title = {{Standards-based Function Shipping - How to use TOSCA for Shipping and Executing Data Analytics Software in Remote Manufacturing Environments}},
   booktitle = {Proceedings of the 2017 IEEE 21st International Enterprise Distributed Object Computing Conference (EDOC 2017)},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {50--60},
   type = {Conference Paper},
   month = {October},
   year = {2017},
   doi = {10.1109/EDOC.2017.16},
   language = {English},
   cr-category = {D.2.13 Software Engineering Reusable Software},
   ee = {http://edoc2017.ca/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The increasing amount of gathered sensor data in Industry 4.0 allows comprehensive data analysis software that creates value-adding opportunities. As companies often cannot implement such software by themselves and as they typically don't want to give their data to external scientists, they commission them to build the required software in order to execute it locally. However, installing, configuring, and running complex third party software on another company's infrastructure and linking them to local data sources challenges the responsible administrators due to an immense technical complexity. Moreover, standards-based approaches for automation are missing. In this paper, we present three TOSCA-based deployment modelling approaches for function shipping that enable modelling data analysis software in a way that enables (i) its automated deployment and execution in a remote, foreign IT infrastructure including (ii) the wiring with the data sources that need to be processed in this environment. We validate the practical feasibility of the presented modelling approaches by a case study from the domain of manufacturing, which is based on the open-source TOSCA ecosystem OpenTOSCA, which provides a modelling tool, a runtime, as well as a self-service portal for TOSCA.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-56&engl=1}
}
@inproceedings {INPROC-2017-54,
   author = {Michael Hahn and Uwe Breitenb{\"u}cher and Frank Leymann and Andreas Wei{\ss}},
   title = {{TraDE - A Transparent Data Exchange Middleware for Service Choreographies}},
   booktitle = {On the Move to Meaningful Internet Systems. OTM 2017 Conferences: Confederated International Conferences: CoopIS, C\&TC, and ODBASE 2017, Rhodes, Greece, October 23-27, 2017, Proceedings, Part I},
   editor = {Herv{\'e} Panetto and Christophe Debruyne and Walid Gaaloul and Mike Papazoglou and Adrian Paschke and Claudio Agostino Ardagna and Robert Meersman},
   publisher = {Springer International Publishing},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science},
   volume = {10573},
   pages = {252--270},
   type = {Conference Paper},
   month = {October},
   year = {2017},
   isbn = {978-3-319-69462-7},
   doi = {10.1007/978-3-319-69462-7_16},
   keywords = {Service choreographies; Data-awareness; Cross-partner data flow; Transparent data exchange; BPM},
   language = {English},
   cr-category = {H.4.1 Office Automation,     C.2.4 Distributed Systems},
   contact = {Michael Hahn: michael.hahn@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Due to recent advances in data science the importance of data is increasing also in the domain of business process management. To reflect the paradigm shift towards data-awareness in service compositions, in previous work, we introduced the notion of data-aware choreographies through cross-partner data objects and cross-partner data flows as means to increase run time flexibility while reducing the complexity of modeling data flows in service choreographies. In this paper, we focus on the required run time environment to execute such data-aware choreographies through a new Transparent Data Exchange (TraDE) Middleware. The contributions of this paper are a choreography language-independent metamodel and an architecture for such a middleware. Furthermore, we evaluated our concepts and TraDE Middleware prototype by conducting a performance evaluation that compares our approach for cross-partner data flows with the classical exchange of data within service choreographies through messages. The evaluation results already show some valuable performance improvements when applying our TraDE concepts.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-54&engl=1}
}
@inproceedings {INPROC-2017-53,
   author = {Sebastian Wagner and Uwe Breitenb{\"u}cher and Oliver Kopp and Andreas Wei{\ss} and Frank Leymann},
   title = {{Fostering the Reuse of TOSCA-based Applications by Merging BPEL Management Plans}},
   booktitle = {Cloud Computing and Services Science: 6th International Conference (CLOSER 2016) - Revised Selected Papers},
   publisher = {Springer International Publishing},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Communications in Computer and Information Science},
   volume = {740},
   pages = {232--254},
   type = {Conference Paper},
   month = {July},
   year = {2017},
   isbn = {978-3-319-62594-2},
   doi = {10.1007/978-3-319-62594-2_12},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-53&engl=1}
}
@inproceedings {INPROC-2017-47,
   author = {Markus Philipp Fischer and Uwe Breitenb{\"u}cher and K{\'a}lm{\'a}n K{\'e}pes and Frank Leymann},
   title = {{Towards an Approach for Automatically Checking Compliance Rules in Deployment Models}},
   booktitle = {Proceedings of The Eleventh International Conference on Emerging Security Information, Systems and Technologies (SECURWARE 2017)},
   publisher = {Xpert Publishing Services},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {150--153},
   type = {Conference Paper},
   month = {September},
   year = {2017},
   isbn = {978-1-61208-582-1},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {An enterprise’s information technology environment is often composed of various complex and heterogeneous systems and is subject to many requirements, regulations, and laws. This leads to the issue that technical experts should also have a firm knowledge about a company’s compliance requirements on information technology. This paper presents an approach to ensure compliance of application deployment models during their design time. We introduce a concept that is able to locate compliance relevant areas in deployment models while also specifying how these areas have to be modeled to fulfill the compliance requirements.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-47&engl=1}
}
@inproceedings {INPROC-2017-45,
   author = {K{\'a}lm{\'a}n K{\'e}pes and Uwe Breitenb{\"u}cher and Markus Philipp Fischer and Frank Leymann and Michael Zimmermann},
   title = {{Policy-Aware Provisioning Plan Generation for TOSCA-based Applications}},
   booktitle = {Proceedings of The Eleventh International Conference on Emerging Security Information, Systems and Technologies (SECURWARE 2017)},
   publisher = {Xpert Publishing Services},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {142--149},
   type = {Conference Paper},
   month = {September},
   year = {2017},
   isbn = {978-1-61208-582-1},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures,     D.4.6 Operating Systems Security and Protection},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-45&engl=1}
}
@inproceedings {INPROC-2017-42,
   author = {Felix W. Baumann and Uwe Breitenb{\"u}cher and Michael Falkenthal and Gerd Gr{\"u}nert and Sebastian Hudert},
   title = {{Industrial Data Sharing with Data Access Policy}},
   booktitle = {Proceedings of the 14th International Conference on Cooperative Design, Visualization, and Engineering (CDVE 2017)},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {215--219},
   type = {Conference Paper},
   month = {September},
   year = {2017},
   keywords = {Industrial Data; Data Aggregation; Policies; Data Hub},
   language = {English},
   cr-category = {C.0 Computer Systems Organization, General,     C.2.4 Distributed Systems,     D.2.2 Software Engineering Design Tools and Techniques,     D.2.3 Software Engineering Coding Tools and Techniques,     D.2.7 Software Engineering Distribution, Maintenance, and Enhancement},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In current industrial settings, data is dispersed on numerous devices, systems and locations without integration and sharing capabilities. With this work, we present a framework for the integration of various data sources within an industrial setting, based on a mediating data hub. Within the data hub, data sources and sinks for this industrial application are equipped with data usage policies to restrict and enable usage and consumption of data for shared analytics. We identify such policies, their requirements and rationale. This work addresses an industrial setting, with manufacturing data being the primary use-case. Requirements for these policies are identified from existing use-cases and expert domain knowledge. The requirements are identified as reasonable via examples and exemplary implementation.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-42&engl=1}
}
@inproceedings {INPROC-2017-39,
   author = {Felix W. Baumann and Oliver Kopp and Dieter Roller},
   title = {{Abstract API for 3D printing hardware and software resources}},
   booktitle = {Int J Adv Manuf Technol},
   publisher = {Springer Nature},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {March},
   year = {2017},
   issn = {0268-3768},
   doi = {10.1007/s00170-017-0260-y},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems;     University of Stuttgart, Institute of Computer-aided Product Development Systems, Computer-aided Product Development Systems},
   abstract = {},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-39&engl=1}
}
@inproceedings {INPROC-2017-29,
   author = {Alfonso Panarello and Uwe Breitenb{\"u}cher and Frank Leymann and Antonio Puliafito and Michael Zimmermann},
   title = {{Automating the Deployment of Multi-Cloud Applications in Federated Cloud Environments}},
   booktitle = {Proceedings of the 10th EAI International Conference on Performance Evaluation Methodologies and Tools (VALUETOOLS)},
   publisher = {ACM},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--8},
   type = {Conference Paper},
   month = {May},
   year = {2017},
   isbn = {978-1-63190-141-6},
   keywords = {Cloud Federation; Federated Multi-Cloud Deployment; Deployment Automation; TOSCA; XMPP},
   language = {English},
   cr-category = {K.6 Management of Computing and Information Systems},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Cloud federation allows cloud providers to dynamically use resources of other federated providers in order to fulfill the requirements of customer requests. This concept enables the federated cloud providers to use external resources for increasing their profit as they do not have to reject customers in case their own resources are occupied. However, (i) comparing the offers of the federated providers in order to decide which provider to use as well as (ii) adapting the installation scripts of the components to be deployed for the different providers is complex, error-prone, and time consuming. In this paper, we present an approach that enables customers to describe their desired application deployments in the form of a topology model that is independent of any concrete provider. We show how this model can be automatically adapted by a provider participating in a cloud federation to deploy components on different other participants. To ensure the practical feasibility of the approach, we employ the TOSCA standard for describing these models and present a technical system architecture based on existing technologies.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-29&engl=1}
}
@inproceedings {INPROC-2017-28,
   author = {Ana Cristina Franco da Silva and Uwe Breitenb{\"u}cher and Pascal Hirmer and K{\'a}lm{\'a}n K{\'e}pes and Oliver Kopp and Frank Leymann and Bernhard Mitschang and Ronald Steinke},
   title = {{Internet of Things Out of the Box: Using TOSCA for Automating the Deployment of IoT Environments}},
   booktitle = {Proceedings of the 7th International Conference on Cloud Computing and Services Science (CLOSER)},
   editor = {Donald Ferguson and V{\'\i}ctor M{\'e}ndez Mu{\~n}oz and Jorge Cardoso and Markus Helfert and Claus Pahl},
   publisher = {SciTePress Digital Library},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {ScitePress},
   volume = {1},
   pages = {358--367},
   type = {Conference Paper},
   month = {June},
   year = {2017},
   isbn = {978-989-758-243-1},
   doi = {10.5220/0006243303580367},
   keywords = {Internet of Things; TOSCA; Application Deployment; Device Software},
   language = {English},
   cr-category = {K.6 Management of Computing and Information Systems,     D.2.12 Software Engineering Interoperability},
   ee = {http://scitepress.org/DigitalLibrary/PublicationsDetail.aspx?ID=AuNrRtS4cNc=&t=1},
   contact = {franco-da-silva@ipvs.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-28&engl=1}
}
@inproceedings {INPROC-2017-27,
   author = {C. Timurhan Sungur and Uwe Breitenb{\"u}cher and Oliver Kopp and Frank Leymann and Andreas Wei{\ss}},
   title = {{Identifying Relevant Resources and Relevant Capabilities of Informal Processes}},
   booktitle = {Proceedings of the 19th International Conference on Enterprise Information Systems (ICEIS 2017)},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {295--307},
   type = {Conference Paper},
   month = {April},
   year = {2017},
   keywords = {Informal Processes; Unstructured Processes; Resource Discovery; Capability Discovery; Relevant Resources; Relevant Capabilities},
   language = {English},
   cr-category = {H.4.1 Office Automation,     H.3.3 Information Search and Retrieval,     H.3.4 Information Storage and Retrieval Systems and Software,     H.5.3 Group and Organization Interfaces},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-27&engl=1}
}
@inproceedings {INPROC-2017-25,
   author = {Karoline Saatkamp and Uwe Breitenb{\"u}cher and Oliver Kopp and Frank Leymann},
   title = {{Topology Splitting and Matching for Multi-Cloud Deployments}},
   booktitle = {Proceedings of the 7th International Conference on Cloud Computing and Services Science (CLOSER 2017)},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {247--258},
   type = {Conference Paper},
   month = {April},
   year = {2017},
   isbn = {978-989-758-243-1},
   keywords = {Application Deployment; Distribution; Splitting; Cloud Computing; TOSCA},
   language = {English},
   cr-category = {G.0 Mathematics of Computing General,     H.0 Information Systems General},
   ee = {http://closer.scitevents.org},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {For automating the deployment of applications in cloud environments, a variety of deployment automation technologies have been developed in recent years. These technologies enable specifying the desired deployment in the form of deployment models, which can be automatically executed. However, changing internal or external conditions often lead to strategical decisions that must be reflected in all deployment models of a company’s IT. Unfortunately, while creating such deployment models is difficult, adapting them is even harder as typically a variety of technologies must be replaced. In this paper, we present the Split and Match Method that enables splitting a deployment model following a manually specified distribution on the business layer. The method also enables automatically deploying the resulting model without the need for a manual intervention and, thus, significantly eases reflecting strategical decisions on the technical deployment layer. We present a formalization and algorithms to automate the steps of the method. Moreover, we validate the practical feasibility of the presented concepts by a prototype based on the TOSCA standard and the OpenTOSCA ecosystem.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-25&engl=1}
}
@inproceedings {INPROC-2017-24,
   author = {Oliver Kopp and Uwe Breitenb{\"u}cher},
   title = {{Choreographies are Key for Distributed Cloud Application Provisioning}},
   booktitle = {ZEUS},
   editor = {Oliver Kopp and J{\"o}rg Lenhard and Cesare Pautasso},
   publisher = {CEUR-WS.org},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {CEUR Workshop Proceedings},
   volume = {1826},
   pages = {67--70},
   type = {Workshop Paper},
   month = {April},
   year = {2017},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://zeus-workshop.eu/2017/,     http://ceur-ws.org/Vol-1826/paper11.pdf},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-24&engl=1}
}
@inproceedings {INPROC-2017-23,
   author = {Christian Endres and Uwe Breitenb{\"u}cher and Frank Leymann and Johannes Wettinger},
   title = {{Anything to Topology - A Method and System Architecture to Topologize Technology-Specific Application Deployment Artifacts}},
   booktitle = {Proceedings of the 7th International Conference on Cloud Computing and Services Science (CLOSER 2017), Porto, Portugal},
   publisher = {SCITEPRESS},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {180--190},
   type = {Conference Paper},
   month = {April},
   year = {2017},
   isbn = {978-989-758-243-1},
   keywords = {Application Deployment; Topology Crawling; TOSCA; Configuration Management; Chef},
   language = {German},
   cr-category = {D.2.9 Software Engineering Management,     D.2.11 Software Engineering Software Architectures,     D.2.13 Software Engineering Reusable Software},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In recent years, many application deployment technologies have emerged such as configuration management tools, e.g., Chef and Juju, infrastructure and platform technologies, e.g., Cloud Foundry and OpenStack, as well as container-based approaches, e.g., Docker. As a result, many repositories exist which contain executable and heavily used artifacts that can be used with these technologies, e.g., to deploy a WordPress application. However, to automate the deployment of more complex applications, typically, multiple of these technologies have to be used in combination. Thus, often, diverse artifacts stored in different repositories need to be integrated. This requires expertise about each technology and leads to a manual, complex, and error-prone integrationstep. Inthispaper, wetackletheseissues: Wepresentamethodandsystemarchitecturethatenables crawling repositories in order to transform the contained artifacts into technology-agnostic topology models, each describing the components that get installed as well as their dependencies. We show how these topologies can be combined to model the deployment of complex applications and how the resulting topology can be deployed automatically by one runtime. To prove the feasibility, we developed and evaluated a prototype based on the TOSCA standard and conducted a case study for Chef artifacts.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-23&engl=1}
}
@inproceedings {INPROC-2017-17,
   author = {Johanna Barzen and Frank Leymann},
   title = {{Patterns as Formulas: Patterns in the Digital Humanities}},
   booktitle = {Proceedings of the Ninth International Conferences on Pervasive Patterns and Applications (PATTERNS)},
   address = {Athen},
   publisher = {Xpert Publishing Services},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {17--21},
   type = {Workshop Paper},
   month = {February},
   year = {2017},
   isbn = {978-1-61208-534-0},
   keywords = {pattern; pattern languages; digital humanities; formalisation},
   language = {English},
   cr-category = {I.5.2 Pattern Recognition Design Methodology,     J.5 Arts and Humanities,     D.3.1 Programming Languages Formal Definitions and Theory},
   contact = {Barzen@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {During the last years, in particular due to the Digital Humanities, empirical processes, data capturing or data analysis got more and more popular as part of humanities research. In this paper, we want to show that even the complete scientific method of natural science can be applied in the humanities. By applying the scientific method to the humanities, certain kinds of problems can be solved in a confirmable and replicable manner. In particular, we will argue that patterns may be perceived as the analogon to formulas in natural science. This may provide a new way of representing solution-oriented knowledge in the humanities.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-17&engl=1}
}
@inproceedings {INPROC-2017-16,
   author = {Michael Zimmermann and Uwe Breitenb{\"u}cher and Frank Leymann},
   title = {{A TOSCA-based Programming Model for Interacting Components of Automatically Deployed Cloud and IoT Applications}},
   booktitle = {Proceedings of the 19th International Conference on Enterprise Information Systems (ICEIS)},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {April},
   year = {2017},
   language = {English},
   cr-category = {D.2.3 Software Engineering Coding Tools and Techniques,     D.2.11 Software Engineering Software Architectures},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Cloud applications typically consist of multiple components interacting with each other. Service-orientation, standards such as WSDL, and the workflow technology provide common means to enable the interaction between these components. Nevertheless, during the automated application deployment, endpoints of interacting components, e.g., URLs of deployed services, still need to be exchanged: the components must be wired. However, this exchange mainly depends on the used (i) middleware technologies, (ii) programming languages, and (iii) deployment technologies, which limits the application’s portability and increases the complexity of implementing components. In this paper, we present a programming model for easing the implementation of interacting components of automatically deployed applications. The presented programming model is based on the TOSCA standard and enables invoking components by their identifiers and interface descriptions contained in the application’s TOSCA model. The approach can be applied to Cloud and IoT applications, i.e., also software hosted on physical devices may use the approach to call other application components. To validate the practical feasibility of the approach, we present a system architecture and prototype based on OpenTOSCA.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-16&engl=1}
}
@inproceedings {INPROC-2017-15,
   author = {Lukas Reinfurt and Uwe Breitenb{\"u}cher and Michael Falkenthal and Frank Leymann and Andreas Riegg},
   title = {{Internet of Things Patterns for Devices}},
   booktitle = {Proceedings of the Ninth international Conferences on Pervasive Patterns and Applications (PATTERNS)},
   publisher = {Xpert Publishing Services},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {117--126},
   type = {Conference Paper},
   month = {February},
   year = {2017},
   keywords = {Internet of Things; Design Patterns; Devices; Constraints},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures,     C.2.4 Distributed Systems},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Devices are an important part of the Internet of Things. They collect data from their environment with sensors and, based on this data, also act on their environment by using actuators. Many use cases require them to support characteristics such as being cheap, light, small, mobile, energy efficient, or autonomously powered. This creates constraints for available energy sources and leads to different kinds of operating modes. Based on existing terminology and additional examples, we describe these energy constraints and the operation modes in the form of Patterns. These Patterns are interconnected with other Patterns to form an Internet of Things Pattern Language that enables practitioners to find and navigate through proven solutions for their problems at hand.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-15&engl=1}
}
@inproceedings {INPROC-2017-14,
   author = {K{\'a}lm{\'a}n K{\'e}pes and Uwe Breitenb{\"u}cher and Frank Leymann},
   title = {{The SePaDe System: Packaging Entire XaaS Layers for Automatically Deploying and Managing Applications}},
   booktitle = {Proceedings of the 7th International Conference on Cloud Computing and Services Science (CLOSER 2017)},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {April},
   year = {2017},
   language = {English},
   cr-category = {D.2.3 Software Engineering Coding Tools and Techniques,     D.2.11 Software Engineering Software Architectures,     D.2.13 Software Engineering Reusable Software},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The multitude of cloud providers and technologies diminish the interoperability and portability of applications by offering diverse and heterogeneous functionalities, APIs, and data models. Although there are integration technologies that provide uniform interfaces that wrap proprietary APIs, the differences regarding the services offered by providers, their functionality, and their management features are still major issues that impede portability. In this paper, we tackle these issues by introducing the SePaDe System, which is a pluggable deployment framework that abstracts from proprietary services, APIs, and data models in a new way: The system builds upon reusable archive templates that contain (i) a deployment model for a certain kind of application and (ii) all deployment and management logic required to provide defined functionalities and management features. Thus, by selecting appropriate templates, an application can be deployed on any infrastructure providing the specified features. We validate the practical feasibility of the approach by a prototypical implementation that is based on the TOSCA standard and present several case studies to evaluate its relevance.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-14&engl=1}
}
@inproceedings {INPROC-2017-12,
   author = {Christian Endres and Uwe Breitenb{\"u}cher and Michael Falkenthal and Oliver Kopp and Frank Leymann and Johannes Wettinger},
   title = {{Declarative vs. Imperative: Two Modeling Patterns for the Automated Deployment of Applications}},
   booktitle = {Proceedings of the 9th International Conference on Pervasive Patterns and Applications (PATTERNS)},
   publisher = {Xpert Publishing Services},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {22--27},
   type = {Conference Paper},
   month = {February},
   year = {2017},
   isbn = {978-1-61208-534-0},
   keywords = {Modeling Patterns; Application Deployment and Management; Automation; Cloud Computing},
   language = {English},
   cr-category = {C.0 Computer Systems Organization, General,     D.2.9 Software Engineering Management,     D.2.13 Software Engineering Reusable Software},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In the field of cloud computing, the automated deployment of applications is of vital importance and supported by diverse management technologies. However, currently there is no systematic knowledge collection that points out commonalities, capabilities, and differences of these approaches. This paper aims at identifying common modeling principles employed by technologies to create automatically executable models that describe the deployment of applications. We discuss two fundamental approaches for modeling the automated deployment of applications: imperative procedural models and declarative models. For these two approaches, we identified (i) basic pattern primitives and (ii) documented these approaches as patterns that point out frequently occurring problems in certain contexts including proven modeling solutions. The introduced patterns foster the understanding of common application deployment concepts, are validated regarding their occurrence in established state-of-the-art technologies, and enable the transfer of that knowledge.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-12&engl=1}
}
@inproceedings {INPROC-2017-10,
   author = {Michael Falkenthal and Frank Leymann},
   title = {{Easing Pattern Application by Means of Solution Languages}},
   booktitle = {Proceedings of the Ninth International Conference on Pervasive Patterns and Applications (PATTERNS)},
   publisher = {Xpert Publishing Services},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {58--64},
   type = {Conference Paper},
   month = {February},
   year = {2017},
   keywords = {Pattern Language; Solution Language; Pattern Application; Solution Selection},
   language = {English},
   cr-category = {C.0 Computer Systems Organization, General,     C.2.4 Distributed Systems,     D.2.2 Software Engineering Design Tools and Techniques,     D.2.3 Software Engineering Coding Tools and Techniques,     D.2.7 Software Engineering Distribution, Maintenance, and Enhancement},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Patterns and pattern languages are a pervasive means to capture proven solutions for frequently recurring problems. They capture the expertise of domain specialists, as well as the essence of concrete solutions in an abstract and generic manner. These characteristics guarantee that patterns and pattern languages are applicable for many concrete use cases. However, due to this nature the knowledge about applying them to concrete problems at hand is lost during the authoring process. The lack of guidance on how to implement a pattern in a specific technical or environmental context leads to immense manual efforts and unnecessary reimplementations of already existing solutions. In our previous work, we presented the concept of linking concrete solutions to patterns in order to ease the pattern application. In this work, we extend this concept and present an approach to organize concrete solutions into Solution Languages, which are means to structure the solution space of a pattern language. We show how Solution Languages can be used to systematically collect specific implementation knowledge to purposefully navigate through a set of concrete solutions to ease and guide the realization of patterns. We validate the approach of Solution Languages in the domain of cloud application architecture and illustrate its technical feasibility by a wiki-based prototype.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-10&engl=1}
}
@inproceedings {INPROC-2017-08,
   author = {Florian Haupt and Frank Leymann and Anton Scherer and Karolina Vukojevic-Haupt},
   title = {{A Framework for the Structural Analysis of REST APIs}},
   booktitle = {Proceedings of the IEEE International Conference on Software Architecture (ICSA 2017)},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {April},
   year = {2017},
   doi = {10.1109/ICSA.2017.40},
   keywords = {REST; interface description language; analysis},
   language = {German},
   cr-category = {D.2.11 Software Engineering Software Architectures},
   contact = {florian.haupt@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Today, REST APIs have established as a means for realizing distributed systems and are supposed to gain even more importance in the context of Cloud Computing, Internet of Things, and Microservices. Nevertheless, many existing REST APIs are known to be not well-designed, resulting in the absence of desirable quality attributes that truly RESTful systems entail. Although existing analysis show, that many REST APIs are not fully REST compliant, it is still an open issue how to improve this deficit and where to start. In this work, we introduce a framework for the structural analysis of REST APIs based on their description documents, as this allows for a comprehensive, well-structured analysis approach that also includes analyzing the corresponding API description languages. A first validation builds on a set of 286 real world API descriptions available as Swagger documents, and comprises their transformation into a canonical metamodel for REST APIs as well as a metrics-based analysis and discussion of their structural characteristics with respect to compliance with the REST architectural style.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2017-08&engl=1}
}
@inproceedings {INPROC-2016-48,
   author = {Jasmin Guth and Uwe Breitenb{\"u}cher and Michael Falkenthal and Frank Leymann and Lukas Reinfurt},
   title = {{Comparison of IoT Platform Architectures: A Field Study based on a Reference Architecture}},
   booktitle = {Cloudification of the Internet of Things (CIoT)},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--6},
   type = {Conference Paper},
   month = {November},
   year = {2016},
   doi = {10.1109/CIOT.2016.7872918},
   keywords = {IoT; CPS; Reference Architecture; OpenMTC; FIWARE; SiteWhere; AWS IoT},
   language = {English},
   cr-category = {C.3 Special-Purpose and Application-Based Systems,     D.2.11 Software Engineering Software Architectures},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The Internet of Things (IoT) is gaining increasing attention. The overall aim is to interconnect the physical with the digital world. Therefore, the physical world needs to be measured and translated into processible data. Further, data has to be translated into commands to be executed by actuators. Due to the growing awareness of IoT, the amount of offered IoT platforms rises as well. The heterogeneity of IoT platforms is the consequence of multiple different standards and approaches. This leads to problems of comprehension, which can occur during the design up to the selection of an appropriate solution. We tackle these issues by introducing an IoT reference architecture based on several state-of-the-art IoT platforms. Furthermore, the reference architecture is compared to three open-source and one proprietary IoT platform. The comparison shows that the reference architecture provides a uniform basis to understand, compare, and evaluate different IoT solutions. The considered state-of-the-art IoT platforms are OpenMTC, FIWARE, Site-Where, and Amazon Web Services IoT.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-48&engl=1}
}
@inproceedings {INPROC-2016-47,
   author = {Michael Falkenthal and Johanna Barzen and Uwe Breitenb{\"u}cher and Christoph Fehling and Frank Leymann and Aristotelis Hadjakos and Frank Hentschel and Heizo Schulze},
   title = {{Leveraging Pattern Applications via Pattern Refinement}},
   booktitle = {Pursuit of Pattern Languages for Societal Change (PURPLSOC)},
   editor = {Peter Baumgartner and Tina Gruber-Muecke and Richard Sickinger},
   address = {Krems},
   publisher = {epubli GmbH},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {38--61},
   type = {Conference Paper},
   month = {October},
   year = {2016},
   keywords = {Pattern Refinement; Pattern Application; Cloud Computing Patterns; Costume Patterns},
   language = {English},
   cr-category = {C.0 Computer Systems Organization, General,     D.2.2 Software Engineering Design Tools and Techniques,     D.2.3 Software Engineering Coding Tools and Techniques,     C.2.4 Distributed Systems,     D.2.7 Software Engineering Distribution, Maintenance, and Enhancement},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In many domains, patterns are a well-established concept to capture proven solutions for frequently reoccurring problems. Patterns aim at capturing knowledge gathered from experience at an abstract level so that proven concepts can be applied to a variety of concrete, individual occurrences of the general problem. While this principle makes a pattern very reusable, it opens up a gap between the (i) captured abstract knowledge and the (ii) concrete actions required to solve a problem at hand. This often results in huge efforts that have to be spent when applying a pattern as its abstract solution has to be refined for the actual, concrete use cases each time it is applied. In this work, we present an approach to bridge this gap in order to support, guide, and ease the application of patterns. We introduce a concept that supports capturing and organizing patterns at different levels of abstraction in order to guide their refinement towards concretized solutions. To show the feasibility of the presented approach, we show how patterns detailing knowledge at different levels of abstraction in the domain of information technology are interrelated in order to ease the labor-intensive application of abstract patterns to concrete use cases. Finally, we sketch a vision of a pattern language for films, which is based on the presented concept.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-47&engl=1}
}
@inproceedings {INPROC-2016-46,
   author = {Lukas Reinfurt and Uwe Breitenb{\"u}cher and Michael Falkenthal and Frank Leymann and Andreas Riegg},
   title = {{Internet of Things Patterns}},
   booktitle = {Proceedings of the 21st European Conference on Pattern Languages of Programs (EuroPLoP)},
   publisher = {ACM},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--21},
   type = {Conference Paper},
   month = {July},
   year = {2016},
   keywords = {Internet of Things; Design Patterns; Cyber-Physical Systems},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures,     C.2.4 Distributed Systems},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The development of the Internet of Things is gaining more and more momentum. Due to its widespread applicability, many different solutions have been created in all kinds of areas and contexts. These include solutions for building automation, industrial manufacturing, logistics and mobility, healthcare, or public utilities, for private consumers, businesses, or government. These solutions often have to deal with similar problems, for example, constrained devices, intermittent connectivity, technological heterogeneity, or privacy and security concerns. But the diversity makes it hard to grasp the underlying principles, to compare different solutions, and to design an appropriate custom implementation in the Internet of Things space. We investigated a large number of production-ready Internet of Things offerings to extract recurring proven solution principles into Patterns, of which five are presented in this paper. These Patterns address several problems. DEVICE GATEWAY shows how to connect devices to a network that do not support the network's technology. DEVICE SHADOW explains how to interact with currently offline devices. With a RULES ENGINE, you can create simple processing rules without programming. DEVICE WAKEUP TRIGGER allows you to get a disconnected device to reconnect to a network when needed. REMOTE LOCK AND WIPE can secure devices and their data in case of loss.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-46&engl=1}
}
@inproceedings {INPROC-2016-40,
   author = {Michael Falkenthal and Uwe Breitenb{\"u}cher and K{\'a}lm{\'a}n K{\'e}pes and Frank Leymann and Michael Zimmermann and Maximilian Christ and Julius Neuffer and Nils Braun and Andreas W. Kempa-Liehr},
   title = {{OpenTOSCA for the 4th Industrial Revolution: Automating the Provisioning of Analytics Tools Based on Apache Flink}},
   booktitle = {Proceedings of the 6th International Conference on the Internet of Things},
   publisher = {ACM},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {179--180},
   type = {Demonstration},
   month = {October},
   year = {2016},
   keywords = {4th Industrial Revolution; Cyber-Physical Systems; Apache Flink; Data Mock Services; Machine Learning; TOSCA},
   language = {English},
   cr-category = {K.6 Management of Computing and Information Systems,     D.2.6 Software Engineering Programming Environments},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The 4th industrial revolution entails new levels of data driven value chain organization and management. In industrial environments, the optimization of whole production lines based on machine learning algorithms allow to generate huge business value. Still, one of the open challenges is how to process the collected data as close to the data sources as possible. To fill this gap, this paper presents an OpenTOSCA-based toolchain that is capable of automatically provisioning Apache Flink as a holistic analytics environment altogether with specialized machine learning algorithms. This stack can be deployed as close to the production line as possible to enable data driven optimization. Further, we demonstrate how the analytics stack can be modeled based on TOSCA to be automatically provisioned considering specific mock services to simulate machine metering in the development phase of the algorithms.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-40&engl=1}
}
@inproceedings {INPROC-2016-39,
   author = {Ana Cristina Franco da Silva and Uwe Breitenb{\"u}cher and K{\'a}lm{\'a}n K{\'e}pes and Oliver Kopp and Frank Leymann},
   title = {{OpenTOSCA for IoT: Automating the Deployment of IoT Applications based on the Mosquitto Message Broker}},
   booktitle = {Proceedings of the 6th International Conference on the Internet of Things (IoT)},
   address = {Stuttgart},
   publisher = {ACM},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {181--182},
   type = {Demonstration},
   month = {November},
   year = {2016},
   isbn = {978-1-4503-4814-0/16/11},
   doi = {10.1145/2991561.2998464},
   keywords = {Internet of Things; Cyber-Physical Systems; Sensor Integration; Message Broker; Mosquitto; MQTT; TOSCA},
   language = {English},
   cr-category = {K.6 Management of Computing and Information Systems,     D.2.12 Software Engineering Interoperability},
   contact = {For questions, feel free to contact me franco-da-silva@ipvs.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Automating the deployment of IoT applications is a complex challenge, especially if multiple heterogeneous sensors, actuators, and business components have to be integrated. This demonstration paper presents a generic, standards-based system that is able to fully automatically deploy IoT applications based on the TOSCA standard, the standardized MQTT messaging protocol, the Mosquitto message broker, and the runtime environment OpenTOSCA. We describe a demonstration scenario and explain in detail how this scenario can be deployed fully automatically using the mentioned technologies.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-39&engl=1}
}
@inproceedings {INPROC-2016-38,
   author = {Andreas Wei{\ss} and Vasilios Andrikopoulos and Santiago G{\'o}mez S{\'a}ez and Michael Hahn and Dimka Karastoyanova},
   title = {{ChorSystem: A Message-Based System for the Life Cycle Management of Choreographies}},
   booktitle = {On the Move to Meaningful Internet Systems: OTM 2016 Conferences: Confederated International Conferences: CoopIS, C\&TC, and ODBASE 2016, Rhodes, Greece, October 24-28, 2016, Proceedings},
   editor = {Christophe Debruyne and Herv{\'e} Panetto and Robert Meersman and Tharam Dillon and Eva K{\"u}hn and Declan O'Sullivan and Claudio Agostino Ardagna},
   publisher = {Springer International Publishing},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {503--521},
   type = {Conference Paper},
   month = {October},
   year = {2016},
   doi = {10.1007/978-3-319-48472-3_30},
   keywords = {Collaborative Dynamic Complex (CDC) Systems; Choreography Life Cycle Management; Flexible Choreographies},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2016-38/INPROC-2016-38.pdf},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Service choreographies are commonly used as the means for enabling inter-organizational collaboration by providing a global view on the message exchange between involved participants. Choreographies are ideal for a number of application domains that are classi ed under the Collaborative, Dynamic \& Complex (CDC) systems area. System users in these application domains require facilities to control the execution of a choreography instance such as suspending, resuming or terminating, and thus actively control its life cycle. We support this requirement by introducing the ChorSystem, a system capable of managing the complete life cycle of choreographies from choreography modeling, through deployment, to execution and monitoring. The performance evaluation of the life cycle operations shows that the ChorSystem introduces an acceptable performance overhead compared to purely script-based scenarios, while gaining the abilities to control the choreography life cycle.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-38&engl=1}
}
@inproceedings {INPROC-2016-37,
   author = {Marigianna Skouradaki and Vasilios Andrikopoulos and Oliver Kopp and Frank Leymann},
   title = {{RoSE: Reoccurring Structures Detection in BPMN 2.0 Process Model Collections}},
   booktitle = {OTM Confederated International Conferences ''On the Move to Meaningful Internet Systems``},
   publisher = {Springer International Publishing},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {263--281},
   type = {Conference Paper},
   month = {October},
   year = {2016},
   isbn = {10.1007/978-3-319-48472-3_15},
   keywords = {BPMN 2.0; Process similarity; Graph matching; Structural similarity; Business process management},
   language = {English},
   cr-category = {D.2.9 Software Engineering Management,     I.2.8 Problem Solving, Control Methods, and Search,     F.2.2 Nonnumerical Algorithms and Problems},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The detection of structural similarities of process models is frequently discussed in the literature. The state-of-the-art approaches for structural similarities of process models presume a known subgraph that is searched in a larger graph, and utilize behavioral and textual semantics to achieve their goal. In this paper we propose an approach to detect reoccurring structures in a collection of BPMN2.0 process models, without the knowledge of a subgraph to be searched, and by focusing solely on the structural characteristics of the process models. The proposed approach deals with the problems of subgraph isomorphism, frequent pattern discovery and maximum common subgraph isomorphism, which are mentioned as NP-hard in the literature. In this work we present a formal model and a novel algorithm for the detection of reoccurring structures in a collection of BPMN 2.0 process models. We then apply the algorithm to a collection of 1,806 real-world process models and provide a quantitative and qualitative analysis of the results.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-37&engl=1}
}
@inproceedings {INPROC-2016-36,
   author = {Marigianna Skouradaki and Tayyaba Azad and Uwe Breitenb{\"u}cher and Oliver Kopp and Frank Leymann},
   title = {{A Decision Support System for the Performance Benchmarking of Workflow Management Systems}},
   booktitle = {Proceedings of the 10th Symposium and Summer School On Service-Oriented Computing, SummerSOC 2016},
   publisher = {IBM},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {41--57},
   type = {Conference Paper},
   month = {September},
   year = {2016},
   keywords = {Decision Support System; Benchmarking; Workflow Managament Systems},
   language = {English},
   cr-category = {H.4.1 Office Automation,     H.4.2 Information Systems Applications Types of Systems,     D.2 Software Engineering,     H.4.2 Information Systems Applications Types of Systems},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Along with the growing popularity of the Workflow Manage- ment Systems, the performance and e ciency of their underlying technol- ogy becomes crucial for the business. The development of a representative benchmark for Workflow Management Systems is very challenging, as one needs to realistically stress the di erent underlying components. However, structured information on how to do so is generally missing. Thus, the users need to arbitrarily make crucial design decisions or to study complex standard benchmarks before designing a benchmark. In this work, we propose a Decision Support System to ease the decision making of the desigh of benchmarks for Workflow Management Systems. We present the conceptual models of the Decision Support System and provide a prototypical implementation of it. Finally, we validate the functionality of our implementation with representative use cases.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-36&engl=1}
}
@inproceedings {INPROC-2016-33,
   author = {Michael Falkenthal and Uwe Breitenb{\"u}cher and Maximilian Christ and Christian Endres and Andreas W. Kempa-Liehr and Frank Leymann and Michael Zimmermann},
   title = {{Towards Function and Data Shipping in Manufacturing Environments: How Cloud Technologies leverage the 4th Industrial Revolution}},
   booktitle = {Proceedings of the 10th Advanced Summer School on Service Oriented Computing},
   publisher = {IBM Research Report},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {IBM Research Report},
   pages = {16--25},
   type = {Conference Paper},
   month = {September},
   year = {2016},
   keywords = {cyber-physical systems; data shipping; fourth industrial revolution; function shipping; tosca; industry 4.0},
   language = {English},
   cr-category = {K.6 Management of Computing and Information Systems,     D.2.13 Software Engineering Reusable Software},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Advances in the field of cloud computing and the Internet of Things are boosting the 4th industrial revolution. New research and developments foster the emergence of smart services, which augment conventional machinery to become smart cyber-physical systems. The resulting systems are characterized by providing preemptive functionality to automatically react on circumstances and changes in their physical environment. In this paper we sketch our vision of how to automatically provision smart services in manufacturing environments, whereby the paradigms of function and data shipping are specifically considered. To base this approach upon a clear understanding of influences, we point out key challenges in the context of smart services for Industry 4.0.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-33&engl=1}
}
@inproceedings {INPROC-2016-28,
   author = {C. Timurhan Sungur and Uwe Breitenb{\"u}cher and Oliver Kopp and Frank Leymann and Mozi Song and Andreas Wei{\ss} and Christoph Mayr-Dorn and Schahram Dustdar},
   title = {{Identifying Relevant Resources and Relevant Capabilities of Collaborations - A Case Study}},
   booktitle = {Proceedings of the 2016 IEEE 20th International Enterprise Distributed Object Computing Workshop (EDOCW)},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {352--355},
   type = {Demonstration},
   month = {September},
   year = {2016},
   keywords = {Organizational performance; resource discovery; capability discovery; relevant resources; relevant capabilities; informal processes; unstructured processes},
   language = {English},
   cr-category = {H.4.1 Office Automation,     H.3.3 Information Search and Retrieval,     H.3.4 Information Storage and Retrieval Systems and Software,     H.5.3 Group and Organization Interfaces},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Organizational processes involving collaborating resources, such as development processes, innovation processes, and decision-making processes, typically affect the performance of many organizations. Moreover, including required but missing, resources and capabilities of collaborations can improve the performance of corresponding processes drastically. In this work, we demonstrate the extended Informal Process Execution (InProXec) method for identifying resources and capabilities of collaborations using a case study on the Apache jclouds project.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-28&engl=1}
}
@inproceedings {INPROC-2016-27,
   author = {K{\'a}lm{\'a}n K{\'e}pes and Uwe Breitenb{\"u}cher and Santiago G{\'o}mez S{\'a}ez and Jasmin Guth and Frank Leymann and Matthias Wieland},
   title = {{Situation-Aware Execution and Dynamic Adaptation of Traditional Workflow Models}},
   booktitle = {Proceedings of the 5th European Conference on Service-Oriented and Cloud Computing (ESOCC)},
   publisher = {Springer International Publishing},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {LNCS},
   volume = {9846},
   pages = {69--83},
   type = {Conference Paper},
   month = {September},
   year = {2016},
   doi = {10.1007/978-3-319-44482-6_5},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The continuous growth of the Internet of Things together with the complexity of modern information systems results in several challenges for modeling, provisioning, executing, and maintaining systems that are capable of adapting themselves to changing situations in dynamic environments. The properties of the workflow technology, such as its recovery features, makes this technology suitable to be leveraged in such environments. However, the realization of situation-aware mechanisms that dynamically adapt process executions to changing situations is not trivial and error prone, since workflow modelers cannot reflect all possibly occurring situations in complex environments in their workflow models. In this paper, we present a method and concepts to enable modelers to create traditional, situation-independent workflow models that are automatically transformed into situation-aware workflow models that cope with dynamic contextual situations. Our work builds upon the usage of workflow fragments, which are dynamically selected during runtime to cope with prevailing situations retrieved from low-level context sensor data. We validate the practical feasibility of our work by a prototypical implementation of a Situation-aware Workflow Management System (SaWMS) that supports the presented concepts.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-27&engl=1}
}
@inproceedings {INPROC-2016-26,
   author = {Michael Hahn and Dimka Karastoyanova and Frank Leymann},
   title = {{A Management Life Cycle for Data-Aware Service Choreographies}},
   booktitle = {Proceedings of the Twenty-Third International Conference on Web Services (ICWS 2016), San Francisco, CA, USA, 2016},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {364--371},
   type = {Conference Paper},
   month = {September},
   year = {2016},
   doi = {10.1109/ICWS.2016.54},
   keywords = {Choreography Management Life Cycle; Data Flow Optimization; Service Choreographies; Transparent Data Exchange},
   language = {English},
   cr-category = {H.4.1 Office Automation,     C.2.4 Distributed Systems},
   contact = {Michael Hahn: michael.hahn@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {This work is motivated by the increasing importance and business value of data in the fields of business process management, scientific workflows as a field in eScience, and Internet of Things, all of which profiting from the recent advances in data science and Big data. We introduce a management life cycle that renders data as first-class citizen in service choreographies and defines the functions and artifacts necessary for enabling transparent and efficient data exchange among choreography participants. The inherent goal of the life cycle, functions and artifacts is to help decouple the data flow, data exchange and management from the control flow in service compositions and choreographies. This decoupling enables peer-to-peer data exchange in choreographies and provides the means for more sophisticated data management and exchange, as well as data exchange and provisioning optimization.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-26&engl=1}
}
@inproceedings {INPROC-2016-25,
   author = {Pascal Hirmer and Matthias Wieland and Uwe Breitenb{\"u}cher and Bernhard Mitschang},
   title = {{Dynamic Ontology-based Sensor Binding}},
   booktitle = {Advances in Databases and Information Systems. 20th East European Conference, ADBIS 2016, Prague, Czech Republic, August 28-31, 2016, Proceedings},
   address = {Prague, Czech Republic},
   publisher = {Springer International Publishing},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Information Systems and Applications, incl. Internet/Web, and HCI},
   volume = {9809},
   pages = {323--337},
   type = {Conference Paper},
   month = {August},
   year = {2016},
   isbn = {978-3-319-44039-2},
   isbn = {978-3-319-44038-5},
   doi = {10.1007/978-3-319-44039-2},
   keywords = {Internet of Things; Sensors; Ontologies; Data Provisioning},
   language = {English},
   cr-category = {E.0 Data General,     B.8 Performance and Reliability},
   ee = {http://www.springer.com/de/book/9783319440385},
   contact = {pascal.hirmer@ipvs.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In recent years, the Internet of Things gains more and more attention through cheap hardware devices and, consequently, an increased interconnection of them. These devices equipped with sensors and actuators form the foundation for so called smart environments that enable monitoring as well as self-organization. However, an efficient sensor registration, binding, and sensor data provisioning is still a major issue for the Internet of Things. Usually, these steps can take up to days or even weeks due to a manual configuration and binding by sensor experts that furthermore have to communicate with domain-experts that define the requirements, e.g. the types of sensors, for the smart environments. In previous work, we introduced a first vision of a method for automated sensor registration, binding, and sensor data provisioning. In this paper, we further detail and extend this vision, e.g., by introducing optimization steps to enhance efficiency as well as effectiveness. Furthermore, the approach is evaluated through a prototypical implementation.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-25&engl=1}
}
@inproceedings {INPROC-2016-24,
   author = {Alexander Bergmayr and Uwe Breitenb{\"u}cher and Oliver Kopp and Manuel Wimmer and Gerti Kappel and Frank Leymann},
   title = {{From Architecture Modeling to Application Provisioning for the Cloud by Combining UML and TOSCA}},
   booktitle = {Proceedings of the 6th International Conference on Cloud Computing and Services Science (CLOSER 2016)},
   publisher = {SCITEPRESS},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {97--108},
   type = {Conference Paper},
   month = {April},
   year = {2016},
   doi = {10.5220/0005806900970108},
   isbn = {978-989-758-182-3},
   keywords = {TOSCA; UML; Model-Driven Software Engineering; Cloud Computing; Cloud Modeling},
   language = {English},
   cr-category = {K.6 Management of Computing and Information Systems},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Recent efforts to standardize a deployment modeling language for cloud applications resulted in TOSCA. At the same time, the software modeling standard UML supports architecture modeling from different viewpoints. Combining these standards from cloud computing and software engineering would allow engineers to refine UML architectural models into TOSCA deployment models that enable automatic provisioning of cloud applications. However, this refinement task is currently carried out manually by recreating TOSCA models from UML models because a conceptual mapping between the two languages as basis for an automated translation is missing. In this paper, we exploit cloud modeling extensions to UML called CAML as the basis for our approach CAML2TOSCA, which aims at bridging UML and TOSCA. The validation of our approach shows that UML models can directly be injected into a TOSCA-based provisioning process. As current UML modeling tools lack cloud-based refinement support for deployment models, the added value of CAML2TOSCA is emphasized because it provides the glue between architecture modeling and application provisioning.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-24&engl=1}
}
@inproceedings {INPROC-2016-23,
   author = {Marigianna Skouradaki and Vasilis Andrikopoulos and Frank Leymann},
   title = {{Representative BPMN 2.0 Process Models Generation from Recurring Structures}},
   booktitle = {Proceedings of the 23rd IEEE International Conference on Web Services, (ICWS 2016)},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {468--475},
   type = {Conference Paper},
   month = {June},
   year = {2016},
   keywords = {BPMN 2.0; Business Process Management; collection; composition; generation; process model; representative},
   language = {English},
   cr-category = {D.2.9 Software Engineering Management,     I.2.8 Problem Solving, Control Methods, and Search,     F.2.2 Nonnumerical Algorithms and Problems},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Representative process models that satisfy specific structural criteria are requested in many different use cases. However, as process models constitute a corporate asset for the companies, they are not easily shared. More particularly, when the requestor desires a process models that satisfy specific structural characteristics, the task of gaining the process models becomes even harder. This work focuses on generating synthetic, representative, executable BPMN 2.0 process models with respect to specific user-defined structural criteria. For the generation of the BPMN 2.0 process models we are using re-curing sub-structures. The discovery of the sub structures has been introduced in previous work.The generated process models will then be utilized for benchmarking purposes. The original scientific contributions of this work are to provide: a) a method for automatically generating executable representative synthetic process models for a given set of structural criteria, b) the proof-of-concept of the proposed method through prototypical implementation and c) qualitative and quantitative evaluation of the proposed approach.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-23&engl=1}
}
@inproceedings {INPROC-2016-21,
   author = {C. Timurhan Sungur and Uwe Breitenb{\"u}cher and Frank Leymann and Matthias Wieland},
   title = {{Context-sensitive Adaptive Production Processes}},
   booktitle = {Proceedings of the 48th CIRP Conference on Manufacturing Systems},
   publisher = {Elsevier},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Procedia CIRP},
   volume = {41},
   pages = {147--152},
   type = {Conference Paper},
   month = {February},
   year = {2016},
   doi = {10.1016/j.procir.2015.12.076},
   keywords = {Process; Automation; Optimization; Adaptation},
   language = {English},
   cr-category = {H.4.1 Office Automation,     H.5.3 Group and Organization Interfaces},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {To stay competitive, manufacturing companies need to adapt their processes in a regular basis to the most recent conditions in their corresponding domains. These adaptations are typically the result of turbulences, such as changes in human resources, new technological advancements, or economic crises. Therefore, to increase the efficiency of production processes, (i) automation, (ii) optimization, and (iii) dynamic adaptation became the most important requirements in this field. In this work, we propose a novel process modelling and execution approach for creating self-organizing processes: Production processes are extended by context-sensitive execution steps, for which sub-processes are selected, elected, optimized, and finally executed on runtime. During the election step, the most desired solution is chosen and optimized based on selection and optimization strategies of the respective processes. Moreover, we present a system architecture for modelling and executing these context-sensitive production processes.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-21&engl=1}
}
@inproceedings {INPROC-2016-19,
   author = {Frank Leymann and Christoph Fehling and Sebastian Wagner and Johannes Wettinger},
   title = {{Native Cloud Applications: Why Virtual Machines, Images and Containers Miss the Point!}},
   booktitle = {Proceedings of the 6th International Conference on Cloud Computing and Service Science (CLOSER 2016)},
   address = {Rome},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {7--15},
   type = {Conference Paper},
   month = {April},
   year = {2016},
   keywords = {Cloud Computing; Virtualization; Cloud Migration; SOA; Microservices; Continuous Delivery},
   language = {English},
   cr-category = {D.2.9 Software Engineering Management,     D.2.11 Software Engineering Software Architectures,     K.6 Management of Computing and Information Systems,     H.4.1 Office Automation},
   contact = {leymann@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Due to the current hype around cloud computing, the term {\^a}€śnative cloud application{\^a}€ť becomes increasingly popular. It suggests an application to fully benefit from all the advantages of cloud computing. Many users tend to consider their applications as cloud native if the application is just bundled in a virtual machine image or a container. Even though virtualization is fundamental for implementing the cloud computing paradigm, a virtualized application does not automatically cover all properties of a native cloud application. In this work, we propose a definition of a native cloud application by specifying the set of characteristic architectural properties, which a native cloud application has to provide. We demonstrate the importance of these properties by introducing a typical scenario from current practice that moves an application to the cloud. The identified properties and the scenario especially show why virtualization alone is insufficient to build native cloud applications. Finally, we outline how native cloud applications respect the core principles of service-oriented architectures, which are currently hyped a lot in the form of microservice architectures.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-19&engl=1}
}
@inproceedings {INPROC-2016-15,
   author = {David Richard Sch{\"a}fer and Andreas Wei{\ss} and Muhammad Adnan Tariq and Vasilios Andrikopoulos and Santiago G{\'o}mez S{\'a}ez and Lukas Krawczyk and Kurt Rothermel},
   title = {{HAWKS: A System for Highly Available Executions of Workflows}},
   booktitle = {Proceedings of the 13th IEEE International Conference on Services Computing: SCC'16; San Francisco, California, USA, June 27-July 2, 2016},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {130--137},
   type = {Conference Paper},
   month = {June},
   year = {2016},
   doi = {10.1109/SCC.2016.24},
   keywords = {SOA; workflows; availability; replication; performance},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     C.4 Performance of Systems},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2016-15/INPROC-2016-15.pdf,     http://dx.doi.org/10.1109/SCC.2016.24},
   department = {University of Stuttgart, Institute of Architecture of Application Systems;     University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {The workflow technology is the de facto standard for managing business processes. Today, workflows are even used for automating interactions and collaborations between business partners, e.g., for enabling just-in-time production. Every workflow that is part of such a collaboration needs to be highly available. Otherwise, the business operations, e.g., the production, might be hindered or even stopped. Since today's business partners are scattered across the globe, the workflows are executed in a highly distributed and heterogeneous environment. Those environments are, however, failure-prone and, thus, providing availability is not trivial. In this work, we improve availability by replicating workflow executions, while ensuring that the outcome is the same as in a non-replicated execution. For making workflow replication easily usable with current workflow technology, we derive the requirements for modeling a workflow replication system. Then, we propose the HAWKS system, which adheres to the previously specified requirements and is compatible with current technology. We implement a proof-of-concept in the open-source workflow execution engine Apache ODE for demonstrating this compatibility. Finally, we extensively evaluate the impact of using HAWKS in terms of performance and availability in the presence of failures.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-15&engl=1}
}
@inproceedings {INPROC-2016-14,
   author = {Vincenzo Ferme and Ana Ivanckikj and Cesare Pautasso and Marigianna Skouradaki and Frank Leymann},
   title = {{A Container-centric Methodology for Benchmarking Workflow Management Systems}},
   booktitle = {Proceedings of the 6th International Conference on Cloud Computing and Service Science, (CLOSER 2016), Rome, Italy, April 22-24, 2016},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {74--84},
   type = {Conference Paper},
   month = {April},
   year = {2016},
   keywords = {Benchmarking; Docker Containers; Workflow Management Systems; Cloud Applications},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     D.2.8 Software Engineering Metrics,     D.2.11 Software Engineering Software Architectures},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Trusted benchmarks should provide reproducible results obtained following a transparent and well-defined process. In this paper, we show how Containers, originally developed to ease the automated deployment of Cloud application components, can be used in the context of a benchmarking methodology. The proposed methodology focuses on Workflow Management Systems (WfMSs), a critical service orchestration middleware, which can be characterized by its architectural complexity, for which Docker Containers offer a highly suitable approach. The contributions of our work are: 1) a new benchmarking approach taking full advantage of containerization technologies; and 2) the formalization of the interaction process with the WfMS vendors described clearly in a written agreement. Thus, we take advantage of emerging Cloud technologies to address technical challenges, ensuring the performance measurements can be trusted. We also make the benchmarking process transparent, automated, and repeatable so that WfMS vendors can join the benchmarking effort.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-14&engl=1}
}
@inproceedings {INPROC-2016-08,
   author = {Sebastian Wagner and Uwe Breitenb{\"u}cher and Frank Leymann},
   title = {{A Method For Reusing TOSCA-based Applications and Management Plans}},
   booktitle = {Proceedings of the 6th International Conference on Cloud Computing and Service Science (CLOSER 2016)},
   address = {Rome},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {181--191},
   type = {Conference Paper},
   month = {April},
   year = {2016},
   language = {English},
   cr-category = {D.2.9 Software Engineering Management,     K.6 Management of Computing and Information Systems,     H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The automated provisioning and management of Cloud applications is supported by various general-purpose technologies that provide generic management functionalities such as scaling components or automatically redeploying parts of a Cloud application. However, if complex applications have to be managed, these technologies reach their limits and individual, application-specific processes must be created to automate the execution of holistic management tasks that cannot be implemented in a generic manner. Unfortunately, creating such processes from scratch is time-consuming, error-prone, and knowledge-intensive, thus, leading to inefficient developments of new applications. In this paper, we present an approach that tackles these issues by enabling the usage of choreographies to systematically combine available management workflows of existing application building blocks. Moreover, we show how these choreographies can be merged into single, executable workflows in order to enable their automated execution. To validate the approach, we apply the concept to the choreography language BPEL4Chor and the Cloud standard TOSCA. In addition, we extend the Cloud application management ecosystem OpenTOSCA to support executing management choreographies.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-08&engl=1}
}
@inproceedings {INPROC-2016-05,
   author = {Marigianna Skouradaki and Vincenzo Ferme and Cesare Pautasso and Frank Leymann and Andr'e van Hoorn},
   title = {{Micro-Benchmarking BPMN 2.0 Workflow Management Systems with Workflow Patterns}},
   booktitle = {28th International Conference, CAiSE 2016, Ljubljana, Slovenia, June 13-17, 2016, Proceedings,Springer Lecture Notes in Computer Science},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {67--82},
   type = {Conference Paper},
   month = {June},
   year = {2016},
   keywords = {Benchmarking; Microbenchmark; Workflow Engine; BPMN 2.0; Workflow Patterns; Workflow Management Systems},
   language = {German},
   cr-category = {D.2.2 Software Engineering Design Tools and Techniques,     D.2.8 Software Engineering Metrics,     D.4.8 Operating Systems Performance},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Although Workflow Management Systems (WfMSs) are a key component in workflow technology, research work for assessing and comparing their performance is limited. This work proposes the first micro- benchmark for WfMSs that can execute BPMN 2.0 workflows. To this end, we focus on studying the performance impact of well-known workflow patterns expressed in BPMN 2.0 with respect to three open source WfMSs (i.e., Activiti, jBPM and Camunda). We executed all the experiments under a reliable environment and produced a set of meaningful metrics. This paper contributes to the area of workflow technology by defining building blocks for more complex BPMN 2.0 WfMS benchmarks. The results have shown bottlenecks on architectural design decisions, resource utilization, and limits on the load a WfMS can sustain, especially for the cases of complex and parallel structures. Experiments on a mix of workflow patterns indicated that there are no unexpected performance side effects when executing different workflow patterns concurrently, although the duration of the individual workflows that comprised the mix was increased.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-05&engl=1}
}
@inproceedings {INPROC-2016-04,
   author = {Michael Hahn and Dimka Karastoyanova and Frank Leymann},
   title = {{Data-Aware Service Choreographies through Transparent Data Exchange}},
   booktitle = {Proceedings of the 16th International Conference on Web Engineering (ICWE'16)},
   publisher = {Springer International Publishing},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science (LNCS)},
   volume = {9671},
   pages = {357--364},
   type = {Conference Paper},
   month = {June},
   year = {2016},
   doi = {10.1007/978-3-319-38791-8_20},
   keywords = {Service Choreographies; Transparent Data Exchange; Decentralized Data Flow; Data Flow Optimization},
   language = {English},
   cr-category = {H.4.1 Office Automation,     C.2.4 Distributed Systems},
   contact = {Michael Hahn: michael.hahn@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Our focus in this paper is on enabling the decoupling of data flow, data exchange and management from the control flow in service compositions and choreographies through novel middleware abstractions and realization. This allows us to perform the data flow of choreographies in a peer-to-peer fashion decoupled from their control flow. Our work is motivated by the increasing importance and business value of data in the fields of business process management, scientific workflows and the Internet of Things, all of which profiting from the recent advances in data science and Big data. Our approach comprises an application life cycle that inherently introduces data exchange and management as a first-class citizen and defines the functions and artifacts necessary for enabling transparent data exchange. Moreover, we present an architecture of the supporting system that contains the Transparent Data Exchange middleware which enables the data exchange and management on behalf of service choreographies and provides methods for the optimization of the data exchange during the execution of service choreographies.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-04&engl=1}
}
@inproceedings {INPROC-2016-03,
   author = {Johanna Barzen and Michael Falkenthal and Frank Hentschel and Frank Leymann and Tino Strehl},
   title = {{{\"A}hnlichkeitssuche in den Digital Humanities: Semi-automatische Identifikation von Kostu\&\#776;mmustern}},
   booktitle = {Konferenzabstracts DHd 2016 ``Modellierung - Vernetzung – Visualisierung: Die Digital Humanities als f{\"a}cher{\"u}bergreifendes Forschungsparadigma''},
   editor = {Elisabeth Burr},
   address = {Leipzig},
   publisher = {nisaba verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {271--273},
   type = {Conference Paper},
   month = {March},
   year = {2016},
   isbn = {ISBN 978-3-941379-05-3},
   keywords = {Costuem-Language; Data-Visualization; Pattern Research; Visual Data Mining, Kost{\"u}m Muster, vestiment{\"a}re Kommunikation},
   language = {German},
   cr-category = {D.2.2 Software Engineering Design Tools and Techniques,     J.5 Arts and Humanities},
   contact = {johanna.barzen@web.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Kost{\"u}me in Filmen sind ein wichtiges Gestaltungselement der diegetischen Welt. Mit MUSE (MUster Suchen und Erkennen) verfolgen wir das Ziel, Konventionen zu identifizieren und zu Mustern zu abstrahieren, die sich entwickelt haben, um Kost{\"u}me als kommunikatives, bedeutungstragendes Element zu nutzen. Hier m{\"o}chten wir vorstellen, wie man die taxonomische Struktur der Daten nutzen kann, um diese nach ihrer {\"A}hnlichkeit hin selektiv auswerten und zu visualisieren, um Hinweise auf m{\"o}gliche Kost{\"u}mmuster zu erhalten.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-03&engl=1}
}
@inproceedings {INPROC-2016-02,
   author = {Vasilios Andrikopoulos and Marina Bitsaki and Santiago G{\'o}mez S{\'a}ez and Michael Hahn and Dimka Karastoyanova and Giorgios Koutras and Alina Psycharaki},
   title = {{Evaluating the Effect of Utility-based Decision Making in Collective Adaptive Systems}},
   booktitle = {Proceedings of the 6th International Conference on Cloud Computing and Service Science (CLOSER 2016)},
   address = {Rome, Italy},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--10},
   type = {Conference Paper},
   month = {April},
   year = {2016},
   language = {German},
   cr-category = {D.2.0 Software Engineering General,     D.2.11 Software Engineering Software Architectures,     D.2.12 Software Engineering Interoperability},
   contact = {Vasilios Andrikopoulos: andrikopoulos@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Utility, defined as the perceived satisfaction with a service, provides the ideal means for decision making on the level of individual entities and collectives participating in a large-scale dynamic system. Previous works have already introduced the concept into the area of collective adaptive systems, and have discussed what is the necessary infrastructure to support the realization of the involved theoretical concepts into actual decision making. In this work we focus on two aspects. First, we provide a concrete utility model for a case study that is part of a larger research project. Second, we incorporate this model into our implementation of the proposed architecture. More importantly, we design and execute an experiment that aims to empirically evaluate the use of utility for decision making by comparing it against simpler decision making mechanisms.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-02&engl=1}
}
@inproceedings {INPROC-2016-01,
   author = {Santiago G{\'o}mez S{\'a}ez and Vasilios Andrikopoulos and Frank Leymann},
   title = {{Consolidation of Performance and Workload Models in Evolving Cloud Application Topologies}},
   booktitle = {Proceedings of the 6th International Conference on Cloud Computing and Service Science (CLOSER 2016)},
   address = {Rome, Italy},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {160--169},
   type = {Conference Paper},
   month = {April},
   year = {2016},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     D.2.8 Software Engineering Metrics,     D.2.11 Software Engineering Software Architectures},
   contact = {Santiago G{\'o}mez S{\'a}ez: santiago.gomez-saez@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The increase of available Cloud services and providers has contributed to accelerate the development and has broaden the possibilities for building and provisioning Cloud applications in heterogeneous Cloud environments. The necessity for satisfying business and operational requirements in an agile and rapid manner has created the need for adapting traditional methods and tooling support for building and provisioning Cloud applications. Focusing on the application's performance and its evolution, we observe a lack of support for specifying, capturing, analyzing, and reasoning on the impact of using different Cloud services and configurations. This paper bridges such a gap by proposing the conceptual and tooling support to enhance Cloud application topology models to capture and analyze the evolution of the application's performance. The tooling support is built upon an existing modeling environment, which is subsequently evaluated using the MediaWiki (Wikipedia) application and its realistic workload.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2016-01&engl=1}
}
@inproceedings {INPROC-2015-57,
   author = {Uwe Breitenb{\"u}cher and Pascal Hirmer and K{\'a}lm{\'a}n K{\'e}pes and Oliver Kopp and Frank Leymann and Matthias Wieland},
   title = {{A Situation-Aware Workflow Modelling Extension}},
   booktitle = {Proceedings of the 17th International Conference on Information Integration and Web-based Applications \& Services (iiWAS 2015)},
   publisher = {ACM},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {478--484},
   type = {Conference Paper},
   month = {December},
   year = {2015},
   keywords = {Situation-Aware Workflows; Workflow Modelling; Workflow Management; Situation-Awareness; Workflow Execution},
   language = {English},
   cr-category = {D.3.3 Programming Language Constructs and Features,     H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The automation of business processes is of vital importance for organizations to speed up their business and to lower costs. Due to emerging technologies in the field of Internet of Things, changing situations can be recognized automatically, which provides the basis for an automated adaptation of process executions in order to react to changing circumstances. Although approaches exist that enable creating self-adapting workflows, a systematic modelling approach that supports the specification of situational dependencies directly in workflow models is missing. In this paper, we tackle this issue by presenting a modelling extension called SitME that defines (i) an extensible Situation Event type, (ii) the concept of Situational Scopes, and (iii) a visual notation. As the introduced extension is language-independent, we apply the approach to BPEL to validate its practical feasibility.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-57&engl=1}
}
@inproceedings {INPROC-2015-56,
   author = {C. Timurhan Sungur and Uwe Breitenb{\"u}cher and Frank Leymann and Johannes Wettinger},
   title = {{Executing Informal Processes}},
   booktitle = {Proceedings of the 17th International Conference on Information Integration and Web-based Applications \& Services (iiWAS 2015)},
   publisher = {ACM},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {391--400},
   type = {Conference Paper},
   month = {December},
   year = {2015},
   keywords = {Informal processes; Agent-centered processes; Human-centric processes; Process execution; TOSCA; APIfication},
   language = {English},
   cr-category = {H.4.1 Office Automation,     H.5.3 Group and Organization Interfaces},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Processes involving knowledge workers, such as decisionmaking processes, research processes, development processes, maintenance processes, etc. play a critical role for many organizations because they represent a valuable amount of the work an organization delivers. Therefore, supporting and automating such processes is vitally important for organizations. In our previous work, we have proposed a resource-centric approach called Informal Process Essentials (IPE) to support and to provide a certain degree of automation. The approach enables specifying required resources including autonomous agents of an informal process for accomplishing process goals through creating and initializing IPE models. Initializing an IPE model results in the acquirement of resources that collaboratively work towards the goals specified by the model. In this work, we provide an approach to automating the enactment of such resource-centric informal processes in two steps: (i) integrating resources of informal processes and (ii) executing informal processes. The approach we introduce enables the inclusion of different resource domains, e.g., IT resources, human resources, etc., and resource deployment environments, e.g., OpenTOSCA, Docker, etc. to model and enact informal processes. During the execution, the resources made available through the integration are acquired and engaged for goals of modeled informal processes. To validate the introduced concepts, we apply the approach to a detailed case study that realizes these two steps based on existing approaches and technologies, in particular, the OpenTOSCA ecosystem, an knowledge base, and an APIfication approach.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-56&engl=1}
}
@inproceedings {INPROC-2015-55,
   author = {Uwe Breitenb{\"u}cher and Tobias Binz and Oliver Kopp and Frank Leymann and Johannes Wettinger},
   title = {{A Modelling Concept to Integrate Declarative and Imperative Cloud Application Provisioning Technologies}},
   booktitle = {Proceedings of the 5th International Conference on Cloud Computing and Services Science (CLOSER 2015)},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {487--496},
   type = {Conference Paper},
   month = {May},
   year = {2015},
   keywords = {Cloud Application Provisioning; Automation; Declarative Modelling; Imperative Modelling},
   language = {English},
   cr-category = {K.6 Management of Computing and Information Systems},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Efficient application provisioning is one of the most important issues in Cloud Computing today. For that purpose, various provisioning automation technologies have been developed that can be generally categorized into two different flavors: (i) declarative approaches are based on describing the desired goals whereas (ii) imperative approaches are used to describe explicit sequences of low-level tasks. Since modern Cloud-based business applications become more and more complex, employ a plethora of heterogeneous components and services that must be wired, and require complex configurations, the two kinds of technologies have to be integrated to model the provisioning of such applications. In this paper, we present a process modelling concept that enables the seamless integration of imperative and declarative provisioning models and their technologies while preserving the strengths of both flavors. We validate the technical feasibility of the approach by applying the concept to the workflow language BPEL and evaluate its features by several criteria.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-55&engl=1}
}
@inproceedings {INPROC-2015-53,
   author = {C. Timurhan Sungur and Christoph Dorn and Schahram Dustdar and Frank Leymann},
   title = {{Transforming Collaboration Structures into Deployable Informal Processes}},
   booktitle = {Proceedings of the 15th International Conference, ICWE 2015, Rotterdam, The Netherlands, June 23-26, 2015.},
   publisher = {Springer International Publishing},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science (LNCS)},
   volume = {9114},
   pages = {231--250},
   type = {Conference Paper},
   month = {June},
   year = {2015},
   isbn = {10.1007/978-3-319-19890-3_16},
   keywords = {Informal process essentials; Human architecture description language; Wiki; Collaboration configuration; Transformation},
   language = {English},
   cr-category = {D.2.2 Software Engineering Design Tools and Techniques,     H.4.1 Office Automation},
   contact = {sungur@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Traditional workflow and activity-centric coordination offers limited process support to human collaborators when unanticipated situations predom- inate. Under such circumstances, informal processes focus on provisioning relevant resources for achieving collaboration goals. Resources include interaction mechanisms such as shared artifact, social networks, and publish/subscribe information dissemination as complex situations typically demand the close collaboration among multiple human process participants. Currently, however, there exists a gap between (i) selecting and configuring suitable interaction mechanisms (collaboration level) and (ii) deploying the respective collaboration platforms (IT level). In this paper, we present an approach and techniques for transforming collaboration structures into automatically deployable informal processes. We demonstrate how our tools support the specification of desirable collaboration capabilities subsequently deployed to multiple MediaWiki instances.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-53&engl=1}
}
@inproceedings {INPROC-2015-51,
   author = {Christoph Fehling and Johanna Barzen and Michael Falkenthal and Frank Leymann},
   title = {{PatternPedia - Collaborative Pattern Identification and Authoring}},
   booktitle = {Proceedings of PURPLSOC (Pursuit of Pattern Languages for Societal Change). The Workshop 2014.},
   publisher = {n.n.},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {252--284},
   type = {Workshop Paper},
   month = {June},
   year = {2015},
   language = {German},
   cr-category = {D.2.1 Software Engineering Requirements/Specifications,     D.2.2 Software Engineering Design Tools and Techniques,     D.3.3 Programming Language Constructs and Features},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The process to identify and author patterns often involves multiple domain experts. This paper introduces PatternPedia – a collaborative tool chain to document existing solutions and manage patterns abstracted from them. We present an extensible pattern metamodel specified in UML to enable this tool support. Sample metamodel extensions are covered for the domain of cloud computing and costumes in films to capture concrete existing solutions and patterns in these domains. Respective solution repositories and pattern repositories have been implemented based on these metamodel extensions. Support for pattern document display, pattern reference visualization, as well as queries on the costume solution repository are presented.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-51&engl=1}
}
@inproceedings {INPROC-2015-50,
   author = {Christoph Fehling and Johanna Barzen and Uwe Breitenb{\"u}cher and Frank Leymann},
   title = {{A Process for Pattern Identification, Authoring, and Application}},
   booktitle = {Proceedings of the 19th European Conference on Pattern Languages of Programs (EuroPLoP)},
   publisher = {ACM},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--9},
   type = {Conference Paper},
   month = {January},
   year = {2015},
   language = {German},
   cr-category = {D.2.1 Software Engineering Requirements/Specifications,     D.2.2 Software Engineering Design Tools and Techniques,     D.3.3 Programming Language Constructs and Features},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The process to identify, author, and apply patterns is mostly performed manually by pattern experts. When performing pattern research in large domains involving many persons, the current state of the art of pattern research techniques, such as shepherding and writers’ workshops, should be extended to a larger organizational process coordinating the work of all involved participants. This paper presents the process we followed to identify, author, and apply patterns in various domains involving multiple industry partners. Due to the diversity of these domains, we claim that the process is general enough to be applicable in other domains as well. This paper documents this process for use, discussion, further refinement, and evaluation in a larger pattern research community.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-50&engl=1}
}
@inproceedings {INPROC-2015-47,
   author = {Oliver Kopp and Michael Falkenthal and Niklas Hartmann and Frank Leymann and Holger Schwarz and Jessica Thomsen},
   title = {{Towards a Cloud-based Platform Architecture for a Decentralized Market Agent}},
   booktitle = {INFORMATIK 2015},
   editor = {Douglas Cunningham and Petra Hofstedt and Klaus Meer and Ingo Schmitt},
   publisher = {Gesellschaft f{\"u}r Informatik e.V. (GI)},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Informatics (LNI)},
   volume = {P-246},
   pages = {69--80},
   type = {Workshop Paper},
   month = {September},
   year = {2015},
   isbn = {978-3-88579-640-4},
   issn = {1617-5468},
   language = {English},
   cr-category = {J.m Computer Applications Miscellaneous},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Reorganization of power generation, thereby replacing conventional energy sources by innovative renewable energy sources, demands a change in distribution grid structure and operation. The foreseen Decentralized Marked Agent is a new role in the energy market sector accomplishing not only trading on energy and operating reserve markets but also regulating flexibilities at the distribution grid level, such as energy storage and decentralized energy generators, and thereby considering system services and securing system stability. This paper presents requirements on an IT system to support this new role.We design an architecture matching these requirements and show how Cloud computing technology can be used to implement the architecture. This enables data concerning the distribution grid being automatically gathered and processed by dedicated algorithms, aiming to optimize cost efficient operation and the development of the distribution grid.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-47&engl=1}
}
@inproceedings {INPROC-2015-46,
   author = {Jessica Thomsen and Niklas Hartmann and Florian Klumpp and Thomas Erge and Michael Falkenthal and Oliver Kopp and Frank Leymann and Sven Stando and Nino Turek and Christoph Schlenzig and Holger Schwarz},
   title = {{Darstellung des Konzeptes -- DMA Decentralised Market Agent -- zur Bew{\"a}ltigung zuk{\"u}nftiger Herausforderungen in Verteilnetzen}},
   booktitle = {INFORMATIK 2015},
   editor = {Douglas Cunningham and Petra Hofstedt and Klaus Meer and Ingo Schmitt},
   publisher = {Gesellschaft f{\"u}r Informatik e.V. (GI)},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Informatics (LNI)},
   volume = {P-246},
   pages = {53--67},
   type = {Workshop Paper},
   month = {September},
   year = {2015},
   isbn = {978-3-88579-640-4},
   issn = {1617-5468},
   language = {German},
   cr-category = {J.m Computer Applications Miscellaneous},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In der vorliegenden Ver{\"o}ffentlichung wird ein Konzept f{\"u}r einen neuen Marktakteur im Strommarkt vorgestellt, der im zuk{\"u}nftigen Smart Grid als Aggregator und Planer fungieren kann. Dieser Decentralised Market Agent – DMA – soll die Informationen aller vorhandenen Erzeugungs- und Speicheranlagen, Lasten und Netzinformationen auf Verteilnetzebene aggregieren sowie mit lokalen Akteuren und an den zentralen M{\"a}rkten agieren um einen kostenoptimalen Betrieb und Ausbau des Systems Verteilnetzes zu realisieren. Zur Handlungsf{\"a}higkeit dieser neuen Marktrolle bedarf es hochaufl{\"o}sender Messungen im Verteilnetz und einer „real-time“ Aufbereitung der Messdaten. Im vorliegenden Paper sollen das Konzept sowie die notwendigen Bausteine zur Erreichung der Handlungsf{\"a}higkeit des DMA vorgestellt sowie die zuk{\"u}nftig geplanten Untersuchungen erl{\"a}utert werden. Die detaillierte Entwicklung des Konzepts sowie weiterf{\"u}hrende Analysen sind Teil des Projektes NEMAR – Netzbewirtschaftung als neue Marktrolle, gef{\"o}rdert durch BMWi im Rahmen der Forschungsinitiative Zukunftsf{\"a}hige Stromnetze.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-46&engl=1}
}
@inproceedings {INPROC-2015-43,
   author = {Karolina Vukojevic-Haupt and Santiago G{\'o}mez S{\'a}ez and Florian Haupt and Dimka Karastoyanova and Frank Leymann},
   title = {{A Middleware-centric Optimization Approach for the Automated Provisioning of Services in the Cloud}},
   booktitle = {Proceedings of the 7th IEEE International Conference on Cloud Computing Technology and Science},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {174--179},
   type = {Conference Paper},
   month = {December},
   year = {2015},
   doi = {10.1109/CloudCom.2015.86},
   keywords = {on-demand provisioning; cloud; service-oriented computing; eScience; optimization; dynamic provisioning; SOC},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     D.2.11 Software Engineering Software Architectures,     I.6.7 Simulation Support Systems},
   contact = {karolina.vukojevic@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The on-demand provisioning of services, a cloud-based extension for traditional service-oriented architectures, improves the handling of services in usage scenarios where they are only used rarely and irregularly. However, the standard process of service provisioning and de-provisioning shows still some shortcomings when applying it in real world. In this paper, we introduce a middleware-centric optimization approach that can be integrated in the existing on-demand provisioning middleware in a loosely coupled manner, changing the standard provisioning and de-provisioning behavior in order to improve it with respect to cost and time. We define and implement a set of optimization strategies, evaluate them based on a real world use case from the eScience domain and provide qualitative as well as quantitative decision support for effectively selecting and parametrizing a suitable strategy. Altogether, our work improves the applicability of the existing on-demand provisioning approach and system in real world, including guidance for selecting the suitable optimization strategy for specific use cases.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-43&engl=1}
}
@inproceedings {INPROC-2015-40,
   author = {Andreas Wei{\ss} and Vasilios Andrikopoulos and Michael Hahn and Dimka Karastoyanova},
   title = {{Rewinding and Repeating Scientific Choreographies}},
   booktitle = {On the Move to Meaningful Internet Systems: OTM 2015 Conferences},
   editor = {H. Panetto et al. C. Debruyne},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {337--347},
   type = {Conference Paper},
   month = {October},
   year = {2015},
   doi = {10.1007/978-3-319-26148-5_22},
   keywords = {Ad Hoc changes; Choreography; Workflow; Flexibility},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Scientists that use the workflow paradigm for the enactment of scientific experiments need support for trial-and-error modeling, as well as flexibility mechanisms that enable the ad hoc repetition of workflow logic for the convergence of results or error handling. Towards this goal, in this paper we introduce the facilities to repeat partially or completely running choreographies on demand. Choreographies are interesting for the scientific workflow community because so-called multi-scale/field (multi-*) experiments can be modeled and enacted as choreographies of scientific workflows. A prerequisite for choreography repetition is the rewinding of the involved participant instances to a previous state. For this purpose, we define a formal model representing choreography models and their instances as well as a concept to repeat choreography logic. Furthermore, we provide an algorithm for determining the rewinding points in each involved participant instance.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-40&engl=1}
}
@inproceedings {INPROC-2015-39,
   author = {Johannes Wettinger and Vasilios Andrikopoulos and Frank Leymann},
   title = {{Enabling DevOps Collaboration and Continuous Delivery Using Diverse Application Environments}},
   booktitle = {Proceedings of the 23rd International Conference on Cooperative Information Systems (CoopIS 2015)},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {October},
   year = {2015},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures,     C.2.4 Distributed Systems},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Aiming to provide the means for efficient collaboration between development and operations personnel, the DevOps paradigm is backed by an increasingly growing collection of tools and reusable artifacts for application management. Continuous delivery pipelines are established based on these building blocks by implementing fully automated, end-to-end application delivery processes, which significantly shorten release cycles to reduce risks and costs as well as gaining a critical competitive advantage. Diverse application environments need to be managed along the pipeline such as development, build, test, and production environments. In this work we address the need for systematically specifying and maintaining diverse application environment topologies enriched with environment-specific requirements in order to implement continuous delivery pipelines. Beside the representation of such requirements, we focus on their systematic and collaborative resolution with respect to the individual needs of the involved application environments.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-39&engl=1}
}
@inproceedings {INPROC-2015-38,
   author = {Johanna Barzen and Frank Leymann},
   title = {{Costume Languages as Pattern Languages}},
   booktitle = {Proceedings of PURPLSOC (Pursuit of Pattern Languages for Societal Change). The Workshop 2014},
   editor = {Peter Baumgartner and Richard Sickinger},
   address = {Krems},
   publisher = {PURPLSOC 2015},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {88--117},
   type = {Workshop Paper},
   month = {June},
   year = {2015},
   isbn = {978-3-7375-5458-9},
   keywords = {Costume Language; Vestimentary Communication; Empirical Film Analysis; Pattern Language; Costumes; Costume Languages; Formal Languages; Digital Humanities},
   language = {English},
   cr-category = {H.3.1 Content Analysis and Indexing,     I.5.2 Pattern Recognition Design Methodology,     J.5 Arts and Humanities,     D.3.1 Programming Languages Formal Definitions and Theory},
   contact = {johanna.barzen@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In media science, the concept of the costume language is only vaguely defined. We propose a formal definition of this concept, which is based on the concept of pattern languages. In order to derive the patterns of such a language we introduce a method that supports capturing knowledge about clothes, identifying costumes based on clothes and abstracting costumes into costume patterns. Thus, costumes are understood as concrete solutions to the recurring problem of achieving effects in films by using clothes. Associations between patterns and concrete solutions are maintained to ease the development of concrete solutions from a patterns abstract solution description. Our method and its associated formalizations are generalized to support the identification of patterns from concrete solutions in other domains.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-38&engl=1}
}
@inproceedings {INPROC-2015-37,
   author = {Johanna Barzen and Michael Falkenthal and Frank Hentschel and Frank Leymann},
   title = {{Musterforschung in den Geisteswissenschaften: Werkzeugumgebung zur Musterextraktion aus Filmkostu\&\#776;men}},
   booktitle = {Extended Abstract Digital Humanities im deutschsprachigen Raum (DHd 2015)},
   address = {Graz},
   publisher = {DHd 2015},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {February},
   year = {2015},
   language = {German},
   cr-category = {J.5 Arts and Humanities,     D.2.2 Software Engineering Design Tools and Techniques},
   contact = {johanna.barzen@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In der Literatur zum Filmkost{\"u}m findet sich immer wieder der Begriff der Kost{\"u}msprache als metaphorische Umschreibung der filmisch vestiment{\"a}ren Kommunikation. Wie diese aber funktioniert, ist nur rudiment{\"a}r untersucht. Um sich den Funktionsweisen und etablierten Konventionen einer Kost{\"u}msprache im Film zu n{\"a}hern, hat sich das Musterkonzept als fruchtbar erwiesen. Um diese Kost{\"u}mmuster als abstrakte L{\"o}sungsprinzipien zu extrahieren, haben wir MUSE, ein Kost{\"u}mrepository zur detaillierten Kost{\"u}merfassung, entwickelt. In diesem Beitrag soll vorgestellt werden, wie die so gesammelten Kost{\"u}m-Daten mittels OLAP Cubes analysiert und ausgewertet werden k{\"o}nnen, um Hinweise auf m{\"o}gliche Muster zu geben.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-37&engl=1}
}
@inproceedings {INPROC-2015-35,
   author = {Santiago G{\'o}mez S{\'a}ez and Vasilios Andrikopoulos and Michael Hahn and Dimka Karastoyanova and Andreas Wei{\ss}},
   title = {{Enabling Reusable and Adaptive Modeling, Provisioning \& Execution of BPEL Processes}},
   booktitle = {Proceedings of the 8th International Conference on Service-Oriented Computing and Applications (SOCA'15)},
   address = {Rome, Italy},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {October},
   year = {2015},
   language = {English},
   cr-category = {H.4.1 Office Automation,     C.2.4 Distributed Systems,     D.2.11 Software Engineering Software Architectures},
   contact = {Santiago G{\'o}mez S{\'a}ez: gomez-saez@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The Business Process Execution Language (BPEL) is a well established language for the definition of process models as service orchestrations. Service orchestrations are used in conjunction with service choreographies in order to create distributed, complex service-based applications. An important requirement for such applications is the need for flexibility during both their modeling and their execution. This work builds on this need by proposing an extension of BPEL in order to allow the definition of abstract constructs on the level of executable process models. Such constructs can be refined to concrete activities at any time, enabling the reuse of existing models and the dynamic adaptation to changing requirements. The design and implementation of the language extension, as well as that of the supporting environment required for the modeling, provisioning, and execution of such process models is further discussed. A case study on a city-wide public transportation system offers the means for an evaluation of the proposed approach.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-35&engl=1}
}
@inproceedings {INPROC-2015-26,
   author = {Marigianna Skouradaki and Frank Leymann},
   title = {{Detecting Frequently Recurring Structures in BPMN 2.0 Process Models}},
   booktitle = {Proceedings of the 9th Symposium and Summer School On Service-Oriented Computing: SummerSOC'14; Heraklion, Greece, June 28 - July 04, 2015},
   publisher = {IBM},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {102--116},
   type = {Conference Paper},
   month = {July},
   year = {2015},
   keywords = {structural similarities; process models; BPMN 2.0; process fragments; subgraph isomorphism},
   language = {German},
   cr-category = {I.2.8 Problem Solving, Control Methods, and Search,     F.2.2 Nonnumerical Algorithms and Problems,     D.2.9 Software Engineering Management},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Reusability of process models is frequently discussed in the literature. Practices of reusability are expected to increase the performance of the designers, because they do not need to start everything from scratch, and the usage of best practices is reinforced. However, the detection of reusable parts and best practices in collections of BPMN 2.0 process models is currently only defined through the experience of experts in this field. In this work we extend an algorithm that detects the recurring structures in a collection of process models. The extended algorithm counts the number of times that a recurring structure appears in a collection of process models, and assigns the corresponding number to its semantics. Moreover, the dublicate entries are eliminated from the collection that contains the extracted recurring structures. In this way, we assert that the resulting collection contains only unique entries. We validate our methodology by applying it on a collection of BPMN 2.0 process models and analyze the results. As shown in the analysis the methodology does not only detect applied practices, but also leads to conclusions of our collection’s special characteristics.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-26&engl=1}
}
@inproceedings {INPROC-2015-25,
   author = {Frank Steimle and Matthias Wieland and Bernhard Mitschang and Sebastian Wagner and Frank Leymann},
   title = {{Design and Implementation Issues of a Secure Cloud-Based Health Data Management System}},
   booktitle = {Proceedings of the 9th Symposium and Summer School On Service-Oriented Computing},
   editor = {Johanna Barzen and Rania Khalaf and Frank Leymann and Bernhard Mitschang},
   publisher = {IBM Research Report},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Technical Paper},
   volume = {RC25564},
   pages = {68--82},
   type = {Conference Paper},
   month = {December},
   year = {2015},
   keywords = {eHealth; mHealth; cloud data; data analysis; security},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     H.2.8 Database Applications,     J.3 Life and Medical Sciences},
   ee = {http://domino.research.ibm.com/library/cyberdig.nsf/papers/656B934403848E8A85257F1D00695A63},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {eHealth gains more and more interest since a lot of end-user devices which support health data capturing are available. The captured data has to be managed and securely stored, in order to access it from different devices and to share it with other users such as physicians. The aim of the German-Greek research project ECHO is to support the treatment of patients, who suffer from Chronic Obstructive Pulmonary Disease (COPD), a chronic respiratory disease. Usually the patients need to be examined by their physicians on a regular basis due to their chronic condition. Since this is very time consuming and expensive, we develop an eHealth system which allows the physician to monitor patients conditions remotely, e.g., via smart phones. Therefore, a secure data processing and sharing eHealth platform is required. In this paper we introduce a health data model and a corresponding platform-architecture for the management and analysis of the data provided by the patients. Furthermore, we show how the security of the data is ensured and we explain how the platform can be hosted in a cloud-based environment using the OASIS standard TOSCA, which enables a self-contained and portable description and management of cloud-services.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-25&engl=1}
}
@inproceedings {INPROC-2015-24,
   author = {Matthias Wieland and Holger Schwarz and Uwe Breitenb{\"u}cher and Frank Leymann},
   title = {{Towards Situation-Aware Adaptive Workflows}},
   booktitle = {Proceedings of the 13th Annual IEEE Intl. Conference on Pervasive Computing and Communications Workshops: 11th Workshop on Context and Activity Modeling and Recognition},
   address = {St. Louis, Missouri, USA},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {32--37},
   type = {Workshop Paper},
   month = {March},
   year = {2015},
   keywords = {situation-awareness; adaptive-workflows; situation recognition; situation-aware workflow system},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Workflows are an established IT concept to achieve business goals in a reliable and robust manner. However, the dynamic nature of modern information systems, the upcoming Industry 4.0, and the Internet of Things increase the complexity of modeling robust workflows significantly as various kinds of situations, such as the failure of a production system, have to be considered explicitly. Consequently, modeling workflows in a situation-aware manner is a complex challenge that quickly results in big unmanageable workflow models. To overcome these issues, we present an approach that allows workflows to become situation-aware to automatically adapt their behavior according to the situation they are in. The approach is based on aggregated context information, which has been an important research topic in the last decade to capture information about an environment. We introduce a system that derives high-level situations from lower-level context and sensor information. A situation can be used by different situation-aware workflows to adapt to the current situation in their execution environment. SitOPT enables the detection of situations using different situation-recognition systems, exchange of information about detected situations, optimization of the situation recognition, and runtime adaption and optimization of situationaware workflows based on the recognized situations.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-24&engl=1}
}
@inproceedings {INPROC-2015-23,
   author = {Karolina Vukojevic-Haupt and Florian Haupt and Frank Leymann and Lukas Reinfurt},
   title = {{Bootstrapping Complex Workflow Middleware Systems into the Cloud}},
   booktitle = {Proceedings of the 11th IEEE International Conference on e-Science},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {126--135},
   type = {Conference Paper},
   month = {September},
   year = {2015},
   doi = {10.1109/eScience.2015.69},
   keywords = {Bootware; Cloud; Bootstrapping; On-demand Provisioning; Dynamic Provisioning; eScience; SOC; Automatic Provisioning; Automatic Deployment; Optimization; Integration},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     D.2.11 Software Engineering Software Architectures},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The use of Cloud infrastructures together with provisioning technologies can be successfully applied in scenarios where resources are only needed rarely and irregularly, for example simulation workflows in the eScience domain. There has already been proposed a solution for the on-demand provisioning of services required by workflows, but how to automatically provision the needed workflow middleware itself is still an open issue. Although many provisioning technologies are available, it is currently not possible to use them in an integrated, flexible and automated way. The main idea presented in this paper is a multistep bootstrapping process, starting with a minimal local software component and ending up with a complex workflow middleware running in the Cloud. This minimal software component is called bootware. We define the key requirements for the bootware, present its architecture and discuss the main design decisions and how they fulfil the requirements. The bootware enables to provision complex workflow middleware systems on-demand and automatically in the Cloud and therefore reduces resource consumption and costs.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-23&engl=1}
}
@inproceedings {INPROC-2015-21,
   author = {Oliver Kopp and Tobias Binz and Uwe Breitenb{\"u}cher and Frank Leymann and Thomas Michelbach},
   title = {{A Domain-Specific Modeling Tool to Model Management Plans for Composite Applications}},
   booktitle = {Proceedings of the 7th Central European Workshop on Services and their Composition, ZEUS 2015},
   editor = {Thomas S. Heinze and Thomas M. Prinz},
   publisher = {CEUR Workshop Proceedings},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {CEUR Workshop Proceedings},
   volume = {1360},
   pages = {51--54},
   type = {Demonstration},
   month = {May},
   year = {2015},
   issn = {1613-0073},
   keywords = {TOSCA; BPMN Extension},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2015-21/INPROC-2015-21.pdf,     http://ceur-ws.org/Vol-1360/,     www.zeus-workshop.eu/2015/},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {TOSCA is a standard to describe composite Cloud-applications and their management in a portable fashion. Thereby, BPMN4TOSCA is a proposed extension for BPMN to ease modeling of management plans. This demonstration presents a web-based modeling tool that supports an updated version of BPMN4TOSCA. The updated version supports direct wiring of data of tasks and events without the need of separate data objects.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-21&engl=1}
}
@inproceedings {INPROC-2015-20,
   author = {Sebastian Wagner and Oliver Kopp and Frank Leymann},
   title = {{Choreography-based Consolidation of Interacting Processes Having Activity-based Loops}},
   booktitle = {Proceedings of the 5th International Conference on Cloud Computing and Service Science (CLOSER 2015)},
   address = {Stuttgart},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {284--296},
   type = {Conference Paper},
   month = {May},
   year = {2015},
   keywords = {BPEL; Choreography; Process Consolidation; Loops},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   contact = {sebastian.wagner@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Choreographies describe the interaction between two or more parties. The interaction behavior description might contain loops. In case two parties want to merge their behavior to gain competitive advantage, the contained loop constructs also have to be merged. This paper presents a language-independent discussion on loop-structure pairing in choreographies and possible merging strategies. Thereby, the focus is turned on loops grouping child activities to be iterated. We show the feasibility of the merging strategies by applying them to BPEL-based choreographies.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-20&engl=1}
}
@inproceedings {INPROC-2015-19,
   author = {Santiago G{\'o}mez S{\'a}ez and Vasilios Andrikopoulos and Roberto Jim{\'e}nez S{\'a}nchez and Frank Leymann and Johannes Wettinger},
   title = {{Dynamic Tailoring and Cloud-based Deployment of Containerized Service Middleware}},
   booktitle = {Proceedings of the 8th International Conference on Cloud Computing (CLOUD 2015)},
   address = {New York, USA},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--8},
   type = {Conference Paper},
   month = {June},
   year = {2015},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures,     C.2.4 Distributed Systems},
   contact = {Santiago G{\'o}mez S{\'a}ez: santiago.gomez-saez@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The emergence and consolidation of container-based virtualization techniques has simplified and accelerated the development, provisioning, and deployment of applications for the Cloud. When considering the case of composite service-based applications that rely on service middleware solutions for their operation, container-based virtualization offers the opportunity for rapid and efficient building and deployment of lightweight, optimally configured middleware instances. As such, it provides an ideal tool for the purposes of cloudifying existing middleware solutions and offering them as part of larger PaaS offerings. As part of this effort, our investigation focuses on leveraging and evaluating a container-based virtualization environment towards enabling the assembly, provisioning, and execution of dynamically tailored instances to satisfy service middleware communication requirements of specific applications. For these purposes we scope the discussion on one particular type of messaging middleware for composite service applications, the Enterprise Service Bus (ESB) technology.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-19&engl=1}
}
@inproceedings {INPROC-2015-18,
   author = {Andreas Wei{\ss} and Vasilios Andrikopoulos and Michael Hahn and Dimka Karastoyanova},
   title = {{Enabling the Extraction and Insertion of Reusable Choreography Fragments}},
   booktitle = {Proceedings of the 22nd IEEE International Conference on Web Services},
   address = {New York},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {686--694},
   type = {Conference Paper},
   month = {June},
   year = {2015},
   doi = {10.1109/ICWS.2015.96},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Reuse of service orchestrations or service compositions is extensively studied in the literature of process modeling. Sub-processes, process templates, process variants, and process reference models are employed as reusable elements for these purposes. The concept of process fragments has been previously introduced in order to capture parts of a process model and store them for later reuse. However, similar efforts on facilitating the reuse of processes that cross the boundaries of organizations expressed as service choreographies are not available yet. In this paper, we introduce the concept of choreography fragments as reusable elements for service choreography modeling. Choreography fragments can be extracted from choreography models, adapted, stored, and later inserted into new models. Based on a formal model for choreography fragments, we define methods and algorithms for the extraction and insertion of fragments from and into service choreographies. We then discuss an experimental and proof-of-concept evaluation of our proposal.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-18&engl=1}
}
@inproceedings {INPROC-2015-17,
   author = {Johannes Wettinger and Uwe Breitenb{\"u}cher and Frank Leymann},
   title = {{DynTail - Dynamically Tailored Deployment Engines for Cloud Applications}},
   booktitle = {Proceedings of the 8th International Conference on Cloud Computing (CLOUD)},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {421--428},
   type = {Conference Paper},
   month = {June},
   year = {2015},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures,     C.2.4 Distributed Systems},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Shortening software release cycles increasingly becomes a critical competitive advantage, not exclusively for software vendors in the field of Web applications, mobile apps, and the Internet of Things. Today's users, customers, and other stakeholders expect quick responses to occurring issues and feature requests. DevOps and Cloud computing are two key paradigms to enable rapid, continuous deployment and delivery of applications utilizing automated software delivery pipelines. However, it is a highly complex and sophisticated challenge to implement such pipelines by installing, configuring, and integrating corresponding general-purpose deployment automation tooling. Therefore, we present a method in conjunction with a framework and implementation to dynamically generate tailored deployment engines for specific application stacks to deploy corresponding applications. Generated deployment engines are packaged in a portable manner to run them on various platforms and infrastructures. The core of our work is based on generating APIs for arbitrary deployment executables such as scripts and plans that perform different tasks in the automated deployment process. As a result, deployment tasks can be triggered through generated API endpoints, abstracting from lower-level, technical details of different deployment automation tooling.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-17&engl=1}
}
@inproceedings {INPROC-2015-14,
   author = {Santiago G{\'o}mez S{\'a}ez and Vasilios Andrikopoulos and Michael Hahn and Dimka Karastoyanova and Frank Leymann and Marigianna Skouradaki and Karolina Vukojevic-Haupt},
   title = {{Performance and Cost Evaluation for the Migration of a Scientific Workflow Infrastructure to the Cloud}},
   booktitle = {Proceedings of the 5th International Conference on Cloud Computing and Service Science (CLOSER 2015)},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {352--361},
   type = {Conference Paper},
   month = {May},
   year = {2015},
   keywords = {Workflow Simulation; eScience; IaaS; Performance Evaluation; Cost Evaluation; Cloud Migration},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     D.2.8 Software Engineering Metrics,     D.2.11 Software Engineering Software Architectures},
   contact = {Santiago G{\'o}mez S{\'a}ez: santiago.gomez-saez@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The success of the Cloud computing paradigm, together with the increase of Cloud providers and optimized Infrastructure-as-a-Service (IaaS) offerings have contributed to a raise in the number of research and industry communities that are strong supporters of migrating and running their applications in the Cloud. Focusing on eScience simulation-based applications, scientific workflows have been widely adopted in the last years, and the scientific workflow management systems have become strong candidates for being migrated to the Cloud. In this research work we aim at empirically evaluating multiple Cloud providers and their corresponding optimized and non-optimized IaaS offerings with respect to their offered performance, and its impact on the incurred monetary costs when migrating and executing a workflow-based simulation environment. The experiments show significant performance improvements and reduced monetary costs when executing the simulation environment in off-premise Clouds.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-14&engl=1}
}
@inproceedings {INPROC-2015-13,
   author = {Marigianna Skouradaki and Vincenzo Ferme and Frank Leymann and Cesare Pautasso and Dieter H. Roller},
   title = {{“BPELanon”: Protect Business Processes on the Cloud}},
   booktitle = {Proceedings of the Fourth International Conference on Cloud Computing and Service Science (CLOSER'15)},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {May},
   year = {2015},
   language = {English},
   cr-category = {D.2.2 Software Engineering Design Tools and Techniques,     D.2.1 Software Engineering Requirements/Specifications},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2015-13/INPROC-2015-13.pdf},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The advent of Cloud computing supports the offering of many Business Process Management applications on a distributed, per-use basis environment through its infrastructure. Due to the fact that privacy is still an open issue in the Cloud, many companies are reluctant to move their Business Processes on a public Cloud. Since the Cloud environment can be beneficiary for the Business Processes, the investigation of privacy issues needs to be further examined. In order to enforce the Business Process sharing on the Cloud we propose a methodology (“BPELanon”) for the anonymization of Business Processes expressed in the Web Service Business Process Execution Language (BPEL). The method transforms a process to preserve its original structure and run-time behavior, while completely anonymizing its business semantics. In this work we set the theoretical framework of the method and define a five management layers architecture to support its realization. We developed a tool that implements the “BPELanon” method, validate its functionality and evaluate its performance against a collection of real-world process models that were conducted in the scope of research projects},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-13&engl=1}
}
@inproceedings {INPROC-2015-12,
   author = {Johannes Wettinger and Uwe Breitenb{\"u}cher and Frank Leymann},
   title = {{Any2API - Automated APIfication}},
   booktitle = {Proceedings of the 5th International Conference on Cloud Computing and Services Science (CLOSER 2015)},
   address = {Stuttgart},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {475--486},
   type = {Conference Paper},
   month = {May},
   year = {2015},
   language = {English},
   cr-category = {D.2.12 Software Engineering Interoperability,     C.2.4 Distributed Systems},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {APIs are a popular means to expose functionality provided by Cloud-based systems, which are utilized to integrate and orchestrate application as well as management functionality in a programmatic manner. In the domain of application management, they are used to fully automate management processes, for example, to deploy Cloud-based Web applications or back-ends for mobile apps. However, as not all required functionality is exposed through an API natively, such processes additionally involve a multitude of other heterogeneous technologies such as scripting languages and deployment automation tooling. Consequently, combining different technologies in an efficient manner is a complex integration challenge. In this paper, we present a generic approach for automatically generating API implementations for arbitrary executables such as scripts and compiled programs, which are not natively exposed as APIs. This APIfication tackles the aforementioned integration challenges by unifying the invocation of heterogeneous technologies while avoiding the costly and manual wrapping of existing executables because it does not scale. We further present the modular and extensible open-source framework Any2API that implements our APIfication approach. Furthermore, we evaluate the approach and the framework by measuring the overhead of generating and using API implementations. In addition, we conduct a detailed case study to confirm the technical feasibility of the approach.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-12&engl=1}
}
@inproceedings {INPROC-2015-10,
   author = {Florian Haupt and Frank Leymann and Cesare Pautasso},
   title = {{A conversation based approach for modeling REST APIs}},
   booktitle = {12th Working IEEE / IFIP Conference on Software Architecture - WICSA 2015},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {May},
   year = {2015},
   language = {German},
   cr-category = {D.2.11 Software Engineering Software Architectures},
   contact = {florian.haupt@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Conversations are a well-known concept in service design to describe complex interactions between a client and one or multiple services. The REST architectural style constrains the characteristics of clients, servers and their interactions in REST architectures which consequently has an impact on conversations in such systems. The relation between conversations and REST architectures and how such RESTful conversations can be characterized has not been studied in detail yet. In this paper we discuss the characteristics of conversations in REST architectures and introduce an initial set of commonly used conversation types. Based on this, we propose to use conversations as a modeling tool for the design of REST APIs at a higher level of abstraction. We also introduce a corresponding interaction centric metamodel for REST APIs. The characterization of RESTful conversations enables a new interaction centric viewpoint on REST architectures which can be also applied for modeling REST APIs on an abstraction level that enables users to focus on the essential functionality of their REST API.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-10&engl=1}
}
@inproceedings {INPROC-2015-09,
   author = {Marigianna Skouradaki and Dieter H. Roller and Frank Leymann and Vincenzo Ferme and Pautasso Cesare},
   title = {{On the Road to Benchmarking BPMN 2.0 Workflow Engines}},
   booktitle = {Proceedings of the 6th ACM/SPEC International Conference on Performance Engineering ICPE 2015, Austin, Texas, January 31 - February 15, 2015},
   publisher = {ACM},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {301--304},
   type = {Conference Paper},
   month = {February},
   year = {2015},
   isbn = {978-1-4503-3248-4},
   keywords = {Benchmarking; Workflow Engine Performance; BPMN 2.0},
   language = {English},
   cr-category = {D.2.8 Software Engineering Metrics,     D.4.8 Operating Systems Performance,     C.4 Performance of Systems},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2015-09/INPROC-2015-09.pdf},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Workow Management Systems (WfMSs) provide platforms for delivering complex service-oriented applications that need to satisfy enterprise-grade quality of service requirements such as dependability and scalability. In this paper we fo- cus on the case of benchmarking the performance of the core of WfMSs, Workow Engines, that are compliant with the Business Process Model and Notation 2.0 (BPMN 2.01) standard. We \_rst explore the main challenges that need to be met when designing such a benchmark and describe the approaches we designed for tackling them in the Bench- Flow project2. We discuss our approach to distill the essence of real-world processes to create from it processes for the benchmark, and to ensure that the benchmark \_nds wide applicability.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-09&engl=1}
}
@inproceedings {INPROC-2015-08,
   author = {Michael Falkenthal and Johanna Barzen and Simon D{\"o}rner and Vadym Elkind and Jan Fauser and Frank Leymann and Tino Strehl},
   title = {{Datenanalyse in den Digital Humanities - Eine Ann{\"a}herung an Kost{\"u}mmuster mittels OLAP Cubes}},
   booktitle = {Datenbanksysteme f{\"u}r Business, Technologie und Web (BTW), 16. Fachtagung des GI-Fachbereichs ``Datenbanken und Informationssysteme'' (DBIS), 02.-06.3.2015 in Hamburg, Germany. Proceedings.},
   publisher = {Lecture Notes in Informatics (LNI)},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Demonstration},
   month = {March},
   year = {2015},
   keywords = {Pattern; Kost{\"u}mpattern; Digital Humanities; OLAP},
   language = {German},
   cr-category = {H.2.8 Database Applications,     H.3.1 Content Analysis and Indexing,     H.3.3 Information Search and Retrieval},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Im Film ist das Kost{\"u}m eines der prominentesten Gestaltungselemente, um Aussagen {\"u}ber eine Rolle, deren Charakter, Stimmung und Transformation, wie auch {\"u}ber Ort- und Zeitgegebenheiten zu kommunizieren. Durch Kost{\"u}mmuster sollen Kost{\"u}mbildner bef{\"a}higt werden, effizient auf bew{\"a}hrte Designl{\"o}sungen zur{\"u}ckgreifen zu k{\"o}nnen. Diese Demo zeigt, wie generelle Designprinzipien aus einer gro{\ss}en Anzahl an Kost{\"u}men aus Filmen f{\"u}r die Entwicklung dieser Kost{\"u}mmuster mittels OLAP Cubes abstrahiert werden k{\"o}nnen. Um generelle Designprinzipien feststellen zu k{\"o}nnen, werden Kost{\"u}me {\"u}ber kategoriale Merkmalstaxonomien beschrieben und in verschiedenen Aggregationsstufen ausgewertet. Die Abstraktion von generellen L{\"o}sungen f{\"u}r Kost{\"u}mmuster wird durch Drill-Down und Roll-Up Mechanismen unterst{\"u}tzt.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-08&engl=1}
}
@inproceedings {INPROC-2015-07,
   author = {Andreas Wei{\ss} and Vasilios Andrikopoulos and Michael Hahn and Dimka Karastoyanova},
   title = {{Fostering Reuse in Choreography Modeling Through Choreography Fragments}},
   booktitle = {Proceedings of the 17th International Conference on Enterprise Information Systems ICEIS 2015},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {28--36},
   type = {Conference Paper},
   month = {April},
   year = {2015},
   doi = {10.5220/0005342000280036},
   keywords = {Choreography; Choreography Fragment; Choreography Fragment Pattern; Choreography Modeling; Reuse},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The concept of reuse in process models is extensively studied in the literature. Sub-processes, process templates, process variants, and process reference models are employed as reusable elements for process modeling. Additionally, the notion of process fragments has been introduced to capture parts of a process model and store them for later reuse. In contrast, concepts for reuse of processes that cross the boundaries of organizations, i.e., choreographies, have not yet been studied in the appropriate level of detail. In this paper, we introduce the concept of choreography fragments as reusable elements for choreography modeling. Choreography fragments can be extracted from choreography models, adapted, stored, and inserted into new models. We provide a formal model for choreography fragments and identify a set of patterns constituting frequently occurring meaningful choreography fragments.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-07&engl=1}
}
@inproceedings {INPROC-2015-04,
   author = {Marigianna Skouradaki and Katharina Goerlach and Michael Hahn and Frank Leymann},
   title = {{Application of Sub-Graph Isomorphism to Extract Reoccurring Structures from BPMN 2.0 Process Models}},
   booktitle = {9th International IEEE Symposium on Service-Oriented System Engineering : SOSE 2015; San Francisco Bay, USA, March 30 - 3, 2015},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--10},
   type = {Conference Paper},
   month = {April},
   year = {2015},
   keywords = {structural similarities; process models; BPMN 2.0; process fragments; subgraph isomorphism},
   language = {English},
   cr-category = {I.2.8 Problem Solving, Control Methods, and Search,     F.2.2 Nonnumerical Algorithms and Problems,     D.2.9 Software Engineering Management},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The state-of-art approaches in structural similarities of process models base their operations on behavioral data and text semantics. These data is usually missing from mock-up or obfuscated process models. This fact makes it complicated to apply current approaches on these types of models. We examine the problem of the automated detection of re-occurring structures in a collection of process models, when text semantics or behavioral data are missing. This problem is a case of (sub)graph isomorphism, which is mentioned as NP-complete in the literature. Since the process models are very special types of attributed directed graphs we are able to develop an approach that runs with logarithmic complexity. In this work we set the theoretical basis, develop a configurable approach for the detection of re-occurring structures in any process models collection, and validate it against a set of BPMN 2.0 models. We define two execution scenarios and discuss the relation of the execution times with the complexity of the comparisons. Finally, we analyze the detected structures, and propose the configurations that lead to optimal results.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-04&engl=1}
}
@inproceedings {INPROC-2015-03,
   author = {Cesare Pautasso and Dieter H. Roller and Vincenzo Ferme and Frank Leymann and Marigianna Skouradaki},
   title = {{Towards Workflow Benchmarking: Open Research Challenges}},
   booktitle = {Proceedings of the 16th Conference on Database Systems for Business, Technology, and Web: Hamburg, Germany, March 2-6, 2015},
   publisher = {-},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--20},
   type = {Conference Paper},
   month = {March},
   year = {2015},
   keywords = {benchmark, workflow management systems, open challenges, BPMN 2.0},
   language = {English},
   cr-category = {H.5.2 Information Interfaces and Presentation User Interfaces},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Workflow Management Systems (WfMS) provide platforms for delivering complex service-oriented applications that need to satisfy enterprise-grade quality of service requirements such as dependability and scalability. The performance of these applications largely depends on the performance of the WfMS supporting them. Comparing the performance of different WfMSs and optimizing their configuration requires that appropriate benchmarks are made available. In this position paper we make the case for benchmarking the performance of WfMSs that are compliant with the Business Process Model and Notation 2.0 standard and explore most of the challenges that one must tackle when constructing such benchmarks.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-03&engl=1}
}
@inproceedings {INPROC-2015-01,
   author = {Johannes Wettinger and Vasilios Andrikopoulos and Frank Leymann},
   title = {{Automated Capturing and Systematic Usage of DevOps Knowledge for Cloud Applications}},
   booktitle = {Proceedings of the IEEE International Conference on Cloud Engineering (IC2E 2015)},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {60--65},
   type = {Conference Paper},
   month = {March},
   year = {2015},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures,     C.2.4 Distributed Systems},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {DevOps is an emerging paradigm to actively foster the collaboration between system developers and operations in order to enable efficient end-to-end automation of software deployment and management processes. DevOps is typically combined with Cloud computing, which enables rapid, on-demand provisioning of underlying resources such as virtual servers, storage, or database instances using APIs in a self-service manner. Today, an ever-growing amount of DevOps tools, reusable artifacts such as scripts, and Cloud services are available to implement DevOps automation. Thus, informed decision making on the appropriate approach(es) for the needs of an application is hard. In this work we present a collaborative and holistic approach to capture DevOps knowledge in a knowledgebase. Beside the ability to capture expert knowledge and utilize crowdsourcing approaches, we implemented a crawling framework to automatically discover and capture DevOps knowledge. Moreover, we show how this knowledge is utilized to deploy and operate Cloud applications.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2015-01&engl=1}
}
@inproceedings {INPROC-2014-79,
   author = {Falko Koetter and Monika Kochanowski and Anette Weisbecker and Christoph Fehling and Frank Leymann},
   title = {{Unifying Compliance Requirements across Business and IT}},
   booktitle = {Proceedings of the IEEE EDOC Conference},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--10},
   type = {Conference Paper},
   month = {September},
   year = {2014},
   language = {English},
   cr-category = {D.2.2 Software Engineering Design Tools and Techniques,     C.2.4 Distributed Systems,     D.2.12 Software Engineering Interoperability},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Ensuring compliance to laws and regulations in their business processes is a burdensome obligation for today’s companies. Compliance requirements cover many areas of business and IT, including process design, deployment and run-time. Past approaches only covered some of these aspects. In this work we introduce a generic compliance descriptor, unifying different technical compliance implementations and keeping the link between laws, requirements and implementations, thus facilitating compliance in face of changes in laws, processes, and IT.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-79&engl=1}
}
@inproceedings {INPROC-2014-77,
   author = {Karolina Vukojevic-Haupt and Florian Haupt and Dimka Karastoyanova and Frank Leymann},
   title = {{Replicability of Dynamically Provisioned Scientific Experiments}},
   booktitle = {IEEE International Conference on Service Oriented Computing \& Applications (SOCA 2014)},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {119--124},
   type = {Conference Paper},
   month = {November},
   year = {2014},
   doi = {10.1109/SOCA.2014.54},
   keywords = {replicability; SOC; SOA; Cloud; on-demand provisioning and deprovisioning; eScience},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     D.2.11 Software Engineering Software Architectures},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The ability to repeat an experiment, known as replicability, is a basic concept of scientific research and also an important aspect in the field of eScience. The principles of Service Oriented Computing (SOC) and Cloud Computing, both based on high runtime dynamicity, are more and more adopted in the eScience domain. Simulation experiments exploiting these principles introduce significant challenges with respect to replicability. Current research activities mainly focus on how to exploit SOC and Cloud for eScience, while the aspect of replicability for such experiments is still an open issue. In this paper we define a general method to identify points of dynamicity in simulation experiments and to handle them in order to enable replicability. We systematically examine different types of service binding strategies, the main source of dynamicity, and derive a method and corresponding architecture to handle this dynamicity with respect to replicability. Our work enables scientists to perform simulation experiments that exploit the dynamicity and flexibility of SOC and Cloud Computing but still are repeatable.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-77&engl=1}
}
@inproceedings {INPROC-2014-72,
   author = {C. Timurhan Sungur and Tobias Binz and Uwe Breitenb{\"u}cher and Frank Leymann},
   title = {{Informal Process Essentials}},
   booktitle = {Proceedings of the 18th IEEE Enterprise Distributed Object Conference (EDOC 2014)},
   address = {Ulm},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {200--209},
   type = {Conference Paper},
   month = {September},
   year = {2014},
   language = {English},
   cr-category = {H.4.1 Office Automation,     K.1 The Computer Industry,     H.1 Models and Principles},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Human-centric processes are part of most organizations and their execution steps are typically not known initially. Consequently, standard business process modeling approaches are not suitable for modeling informal processes because they typically concentrate on the explicit modeling of the execution steps. In this work, we analyze properties of informal processes and requirements for supporting their correct enactment. We review existing approaches and evaluate their suitability in terms of modeling informal processes. Based on these results, we present a resource-centric approach by employing the concept of Informal Process Essentials which is used to create executable informal process models with dynamically changing interrelated resources.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-72&engl=1}
}
@inproceedings {INPROC-2014-71,
   author = {Michael Hahn and Santiago G{\'o}mez S{\'a}ez and Vasilios Andrikopoulos and Dimka Karastoyanova and Frank Leymann},
   title = {{Development and Evaluation of a Multi-tenant Service Middleware PaaS Solution}},
   booktitle = {Proceedings of the 7th International Conference on Utility and Cloud Computing (UCC 2014)},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {278--287},
   type = {Conference Paper},
   month = {December},
   year = {2014},
   doi = {10.1109/UCC.2014.37},
   keywords = {Multi-tenancy; Cloud middleware; PaaS; Performance Evaluation},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     H.4.1 Office Automation},
   contact = {Michael Hahn: michael.hahn@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In many modern systems, applications or services are realized as compositions of multiple existing services that can be enacted by Service Composition Engines (SCEs), which provide the required functionality to enable their definition and execution. SCEs typically use the capabilities of an Enterprise Service Bus (ESB) which serves as the messaging hub between the composed services aiming at ensuring their integration. Together, an SCE and ESB solution comprise the service middleware required for the definition and execution of service-based composite applications. Offering a service middleware solution as a service creates a PaaS offering that allows the service consumers to share the service middleware solution in a multi-tenant manner. However, multi-tenancy support for service middleware solutions remains an open issue. For this purpose, in this work we introduce a general architecture for the realization of a multi-tenant service middleware PaaS solution. This architecture is prototypically realized based on open-source, multi-tenant ESB and SCE solutions. The resulting service middleware provides configurability for service compositions, tenant-aware messaging, and tenant-based administration and management of the SCE and the ESB. We also present an empirical evaluation of the multi-tenant service middleware with focus on the SCE. The results of these experiments show a performance degradation within acceptable limits when scaling the number of tenants and tenant users.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-71&engl=1}
}
@inproceedings {INPROC-2014-70,
   author = {Santiago G{\'o}mez S{\'a}ez},
   title = {{Design Support for Performance-aware Cloud Application (Re-)Distribution}},
   booktitle = {Proceedings of the PhD Symposium at the 3rd European Conference on Service-Oriented and Cloud Computing (ESOCC 2014)},
   publisher = {Jenaer Schriften zur Mathematik und Informatik},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {6--11},
   type = {Conference Paper},
   month = {September},
   year = {2014},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures,     C.2.4 Distributed Systems},
   contact = {Santiago G{\'o}mez S{\'a}ez: gomez-saez@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The Cloud computing paradigm emerged by establishing innovative resources provisioning and consumption models. Together with the improvement of resource management techniques, these models have contributed to an increase in the number of application developers that are strong supporters of partially or completely migrating their application to a highly scalable and pay-per-use infrastructure. However, due to the continuous growth of Cloud providers and Cloud offerings, Cloud application developers nowadays must face additional application design challenges related to the efficient selection of such offerings to optimally distribute the application in a Cloud infrastructure. Focusing on the performance aspects of the application, additional challenges arise, as application workloads fluctuate over time, and therefore produce a variation of the infrastructure resources demands. In this research work we aim to define and realize the underpinning concepts towards supporting the optimal (re-)distribution of an application in the Cloud in order to handle fluctuating over time workloads.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-70&engl=1}
}
@inproceedings {INPROC-2014-69,
   author = {Michael Hahn and Santiago G{\'o}mez S{\'a}ez and Vasilios Andrikopoulos and Dimka Karastoyanova and Frank Leymann},
   title = {{SCE^MT: A Multi-tenant Service Composition Engine}},
   booktitle = {Proceedings of the 7th International Conference on Service-Oriented Computing and Applications (SOCA'14)},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {89--96},
   type = {Conference Paper},
   month = {November},
   year = {2014},
   doi = {10.1109/SOCA.2014.9},
   keywords = {Multi-tenancy; Service Composition Engine; Cloud middleware; Performance Evaluation},
   language = {English},
   cr-category = {C.2.4 Distributed Systems},
   contact = {Michael Hahn: michael.hahn@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The support of multi-tenancy is an essential requirement for leveraging the full capacity of Cloud computing. Multi-tenancy enables service providers to maximize the utilization of their infrastructure and to reduce the servicing costs per customer, thus indirectly benefiting also the customers. In addition, it allows both providers and consumers to reap the advantages of Cloud-based applications configurable for the needs of different tenants. Nowadays, new applications or services are typically compositions of multiple existing services. Service Composition Engines (SCEs) provide the required functionality to enable the definition and execution of such compositions. Multi-tenancy on the level of SCEs allows for both process model, as well as underlying infrastructure sharing. Towards the goal of enabling multi-tenancy of SCEs, in this paper, we investigate the requirements and define a general architecture for the realization of a multi-tenant SCE solution. This architecture is prototypically realized based on an open-source SCE implementation and integrated into an existing multi-tenant aware Enterprise Service Bus (ESB). The performance evaluation of our prototype shows promising results in terms of the degradation introduced due to processing and communication overhead.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-69&engl=1}
}
@inproceedings {INPROC-2014-68,
   author = {Johannes Wettinger and Uwe Breitenb{\"u}cher and Frank Leymann},
   title = {{Standards-based DevOps Automation and Integration Using TOSCA}},
   booktitle = {Proceedings of the 7th International Conference on Utility and Cloud Computing (UCC 2014)},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {59--68},
   type = {Conference Paper},
   month = {December},
   year = {2014},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures,     C.2.4 Distributed Systems},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {DevOps is an emerging paradigm to tightly integrate developers with operations personnel. This is required to enable fast and frequent releases in the sense of continuously delivering software. Users and customers of today's Web applications and mobile apps running in the Cloud expect fast feedback to problems and feature requests. Thus, it is a critical competitive advantage to be able to respond quickly. Beside cultural and organizational changes that are necessary to implement DevOps in practice, tooling is required to implement end-to-end automation of deployment processes. Automation is the key to efficient collaboration and tight integration between development and operations. The DevOps community is constantly pushing new approaches, tools, and open-source artifacts to implement such automated processes. However, as all these proprietary and heterogeneous DevOps automation approaches differ from each other, it is hard to integrate and combine them to deploy applications in the Cloud. In this paper we present a systematic classification of DevOps artifacts and show how different kinds of artifacts can be transformed toward TOSCA, an emerging standard in this field. This enables the seamless and interoperable orchestration of arbitrary artifacts to model and deploy application topologies. We validate the presented approach by a prototype implementation, show its practical feasibility by a detailed case study, and evaluate its performance.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-68&engl=1}
}
@inproceedings {INPROC-2014-66,
   author = {Pascal Hirmer and Uwe Breitenb{\"u}cher and Tobias Binz and Frank Leymann},
   title = {{Automatic Topology Completion of TOSCA-based Cloud Applications}},
   booktitle = {Proceedings des CloudCycle14 Workshops auf der 44. Jahrestagung der Gesellschaft f{\"u}r Informatik e.V. (GI)},
   address = {Bonn},
   publisher = {Gesellschaft f{\"u}r Informatik e.V. (GI)},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {LNI},
   volume = {232},
   pages = {247--258},
   type = {Workshop Paper},
   month = {September},
   year = {2014},
   isbn = {978-3-88579-626-8},
   keywords = {TOSCA; Automatic Topology Completion; Provisioning; Cloud Computing; Topology Modeling},
   language = {English},
   cr-category = {K.6 Management of Computing and Information Systems},
   ee = {http://subs.emis.de/LNI/Proceedings/Proceedings232/article82.html},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Automation of application provisioning is one of the key aspects of Cloud Computing. Standards such as the Topology and Orchestration Specification for Cloud Applications (TOSCA) provide a means to model application topologies which can be provisioned fully automatically. Many automated provisioning engines require that these topologies are complete in the sense of specifying all application, platform, and infrastructure components. However, modeling complete models is a complex, timeconsuming, and error-prone task that typically requires a lot of technical expertise. In this paper, we present an approach that enables users to model incomplete TOSCA application topologies that are completed automatically to deployable, complete models. This enables users to focus on the business-relevant application components and simplifies the creation process tremendously by minimizing the required effort and know-how. We prove the technical feasibility of the presented approach by a prototypical implementation based on the open source modeling tool Winery. In addition, we evaluate the approach by standards-compliance and performance.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-66&engl=1}
}
@inproceedings {INPROC-2014-63,
   author = {Alexander Blehm and Volha Kalach and Alexander Kicherer and Gustav Murawski and Tim Waizenegger and Matthias Wieland},
   title = {{Policy-Framework – Eine Methode zur Umsetzung von Sicherheits-Policies im Cloud-Computing}},
   booktitle = {Proceedings des CloudCycle14 Workshops auf der 44. Jahrestagung der Gesellschaft f{\"u}r Informatik e.V. (GI)},
   publisher = {Gesellschaft f{\"u}r Informatik e.V. (GI)},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {LNI},
   type = {Workshop Paper},
   month = {September},
   year = {2014},
   language = {German},
   cr-category = {K.6 Management of Computing and Information Systems},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Cloud-Computing gewinnt immer mehr an Bedeutung bei der kosteneffizienten und skalierbaren Bereitstellung von IT-Diensten. Damit sich Cloud-Computing jedoch durchsetzen kann, muss die Sicherheit und Compliance der Dienste garantiert werden, d. h. die Einhaltung von Gesetzen, Richtlinien und Datenschutzvorgaben. Um diese Ziele zu erreichen, wird in diesem Beitrag ein Policy-Framework vorgestellt, welches die Umsetzung von Sicherheits- Policies im Cloud-Computing erm{\"o}glicht. Eine Policy beschreibt dabei nicht-funktionale Anforderungen an Cloud-Dienste. Des weiteren werden verschiedene prototypisch umgesetzte Policies beschieben und es wird ein Moodle- System als Anwendungsbeispiel f{\"u}r einen Cloud-Dienst mit den vorhandenen Policies annotiert. Dadurch erfolgt eine Evaluation des Policy-Frameworks.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-63&engl=1}
}
@inproceedings {INPROC-2014-62,
   author = {Uwe Breitenb{\"u}cher and Tobias Binz and Frank Leymann},
   title = {{A Method to Automate Cloud Application Management Patterns}},
   booktitle = {Proceedings of the Eighth International Conference on Advanced Engineering Computing and Applications in Sciences (ADVCOMP 2014)},
   publisher = {Xpert Publishing Services},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {140--145},
   type = {Conference Paper},
   month = {August},
   year = {2014},
   isbn = {978-1-61208-354-4},
   keywords = {Application Management; Cloud Computing; Management Patterns; Management Automation},
   language = {English},
   cr-category = {D.2.7 Software Engineering Distribution, Maintenance, and Enhancement,     D.2.9 Software Engineering Management,     K.6 Management of Computing and Information Systems,     K.6.3 Software Management},
   ee = {http://thinkmind.org/index.php?view=article&articleid=advcomp_2014_7_30_20143},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Management patterns are a well-established concept to document reusable solutions for recurring application management issues in a certain context. Their generic nature provides a powerful means to describe application management knowledge in an abstract fashion that can be refined for individual use cases manually. However, manual refinement of abstract management patterns for concrete applications prevents applying the concept of patterns efficiently to the domain of Cloud Computing, which requires a fast and immediate execution of arising management tasks. Thus, the application of management patterns must be automated to fulfill these requirements. In this paper, we present a method that guides the automation of Cloud Application Management Patterns using the Management Planlet Framework, which enables applying them fully automatically to individual running applications. We explain how existing management patterns can be implemented as Automated Management Patterns and show how these implementations can be tested afterwards to ensure their correctness. To validate the approach, we conduct a detailed case study on a real migration scenario.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-62&engl=1}
}
@inproceedings {INPROC-2014-61,
   author = {Marina Bitsaki and Christos Koutras and Georgios Koutras and Frank Leymann and Bernhard Mitschang and Christos Nikolaou and Nikos Siafakas and Steve Strauch and Nikos Tzanakis and Matthias Wieland},
   title = {{An Integrated mHealth Solution for Enhancing Patients' Health Online}},
   booktitle = {Proceedings of the 6th European Conference of the International Federation for Medical and Biological Engineering (MBEC'14)},
   publisher = {International Federation for Medical and Biological Engineering (IFMBE)},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--4},
   type = {Conference Paper},
   month = {September},
   year = {2014},
   keywords = {Patient monitoring; COPD; ICT application services; Cloud technology; Online services; Mobile applications; Intelligent data mining},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     H.2.8 Database Applications,     H.4.1 Office Automation,     J.3 Life and Medical Sciences},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2014-61/INPROC-2014-61.pdf},
   contact = {a href=``http://www.iaas.uni-stuttgart.de/institut/mitarbeiter/strauch''Steve Strauch/ a},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Lack of time or economic difficulties prevent chronic obstructive pulmonary disease patients from communicating with their physicians, thus inducing exacerbation of their chronic condition and possible hospitalization. In this paper we propose a platform that integrates mobile application technologies and cloud computing to provide regular monitoring of patients and avoidance of medical emergencies.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-61&engl=1}
}
@inproceedings {INPROC-2014-60,
   author = {Andreas Wei{\ss} and Santiago G{\'o}mez S{\'a}ez and Michael Hahn and Dimka Karastoyanova},
   title = {{Approach and Refinement Strategies for Flexible Choreography Enactment}},
   booktitle = {22nd International Conference on Cooperative Information Systems (CoopIS 2014)},
   editor = {H. Panetto et al. R. Meersman},
   publisher = {Springer Berlin Heidelberg},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {93--111},
   type = {Conference Paper},
   month = {October},
   year = {2014},
   doi = {10.1007/978-3-662-45563-0_6},
   keywords = {Process Flexibility, Choreography Flexibility, Refinement Strategies, Late Modeling, Late Selection, Process Fragments},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Collaborative, Dynamic \& Complex (CDC) systems such as adaptive pervasive systems, eScience applications, and complex business systems inherently require modeling and run time exibility. Since domain problems in CDC systems are expressed as service choreographies and enacted by service orchestrations, we propose an approach introducing placeholder modeling constructs usable both on the level of choreographies and orchestrations, and a classi cation of strategies for their re nement to executable work ows. These abstract modeling constructs allow deferring the modeling decisions to later points in the life cycle of choreographies. This supports run time scenarios such as incorporating new participants into a choreography after its enactment has started or enhancing the process logic of some of the participants. We provide a prototypical implementation of the approach and evaluate it by means of a case study.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-60&engl=1}
}
@inproceedings {INPROC-2014-57,
   author = {David Richard Sch{\"a}fer and Santiago G{\'o}mez S{\'a}ez and Thomas Bach and Vasilios Andrikopoulos and Muhammad Adnan Tariq},
   title = {{Towards Ensuring High Availability in Collective Adaptive Systems}},
   booktitle = {Proceedings of the First International Workshop of Business Processes in Collective Adaptive Systems: BPCAS'14; Eindhoven, Netherlands, September 8, 2014},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Workshop Paper},
   month = {September},
   year = {2014},
   keywords = {workflows; high availability; service discovery; process fragment injection},
   language = {English},
   cr-category = {D.2.0 Software Engineering General,     D.2.11 Software Engineering Software Architectures,     D.2.12 Software Engineering Interoperability,     C.2.4 Distributed Systems,     C.4 Performance of Systems},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2014-57/INPROC-2014-57.pdf},
   contact = {david.schaefer@ipvs.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems;     University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {Collective Adaptive Systems support the interaction and adaptation of virtual and physical entities towards achieving common objectives. For these systems, several challenges at the modeling, provisioning, and execution phases arise. In this position paper, we define the necessary underpinning concepts and identify requirements towards ensuring high availability in such systems. More specifically, based on a scenario from the EU Project ALLOW Ensembles, we identify the necessary requirements and derive an architectural approach that aims at ensuring high availability by combining active workflow replication, service selection, and dynamic compensation techniques.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-57&engl=1}
}
@inproceedings {INPROC-2014-56,
   author = {Johannes Wettinger and Uwe Breitenb{\"u}cher and Frank Leymann},
   title = {{Compensation-based vs. Convergent Deployment Automation for Services Operated in the Cloud}},
   booktitle = {Proceedings of the 12th International Conference on Service-Oriented Computing (ICSOC 2014)},
   publisher = {Springer-Verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {336--350},
   type = {Conference Paper},
   month = {November},
   year = {2014},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures,     C.2.4 Distributed Systems},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Leading paradigms to develop and operate applications such as continuous delivery, configuration management, and the merge of development and operations (DevOps) are the foundation for various techniques and tools to implement automated deployment. To expose such applications as services (SaaS) to users and customers these approaches are typically used in conjunction with Cloud computing to automatically provision and manage underlying resources such as storage or virtual machines. A major class of these automation approaches follows the idea of converging toward a desired state of a resource (e.g., a middleware component deployed on a virtual machine). This is achieved by repeatedly executing idempotent scripts until the desired state is reached. Because of major drawbacks of this approach, we present an alternative deployment automation approach based on compensation and fine-grained snapshots using container virtualization. We further perform an evaluation comparing both approaches in terms of difficulties at design time and performance at runtime.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-56&engl=1}
}
@inproceedings {INPROC-2014-53,
   author = {C. Timurhan Sungur and Oliver Kopp and Frank Leymann},
   title = {{Supporting Informal Processes}},
   booktitle = {The 6th Central European Workshop on Services and their Composition (ZEUS 2014)},
   address = {Potsdam},
   publisher = {CEUR-WS.org},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {56--63},
   type = {Workshop Paper},
   month = {February},
   year = {2014},
   keywords = {ad-hoc processes, informal processes, informal processes support model, informal process essentials, informal process recommendations},
   language = {English},
   cr-category = {H.1 Models and Principles,     K.1 The Computer Industry},
   contact = {timurhan.sungur@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {People play an indispensable role in many tasks in various domains and they collaborate to accomplish those tasks. During these collaborations software tools are used, data is created/consumed and best practices might be applied. These a priori unknown informal processes are conducted with the help of experience of their actual performers. In this work, a new concept of supporting these informal processes will be introduced, i.e., Informal Process Support Model, consisting of Informal Process Essentials and Informal Process Recommendations, which support informal processes based on the previous executions without limiting their flexibility. Furthermore, we will introduce how these concepts can be realized with the use of Topology Orchestration Specification for Cloud Applications (TOSCA).},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-53&engl=1}
}
@inproceedings {INPROC-2014-52,
   author = {Peter Reimann and Tim Waizenegger and Matthias Wieland and Holger Schwarz},
   title = {{Datenmanagement in der Cloud f{\"u}r den Bereich Simulationen und Wissenschaftliches Rechnen}},
   booktitle = {Proceedings des 2. Workshop Data Management in the Cloud auf der 44. Jahrestagung der Gesellschaft f{\"u}r Informatik e.V. (GI)},
   editor = {Gesellschaft f{\"u}r Informatik e.V. (GI)},
   address = {Stuttgart, Deutschland},
   publisher = {Lecture Notes in Informatics (LNI)},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Workshop Paper},
   month = {September},
   year = {2014},
   language = {German},
   cr-category = {H.2.5 Heterogeneous Databases,     H.2.8 Database Applications,     H.4.1 Office Automation},
   contact = {Peter Reimann Peter.Reimann@ipvs.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {F{\"u}r Organisationen, die Simulationen nicht als ihr Kerngesch{\"a}ft verstehen und sie daher eher sporadisch durchf{\"u}hren, lohnt sich der Betrieb einer eigenen Recheninfrastruktur nur selten. Dies betrifft z.B. kleine und mittlere Unternehmen sowie einige wissenschaftliche Institutionen. Besserung k{\"o}nnen {\"o}ffentliche Cloud-Infrastrukturen als Plattform f{\"u}r die Ausf{\"u}hrung von Simulationen verschaffen. Das Datenmanagement in der Cloud ist aber speziell f{\"u}r den Bereich Simulationen noch weitgehend unerforscht. In diesem Beitrag identifizieren wir daher noch offene Fragestellungen bzgl. des Datenmanagements von Simulationen in der Cloud. Dies betrifft vor allem die Datenbereitstellung und inwieweit nutzer- und simulationsspezifische Anforderungen an das Datenmanagement in der Cloud eingehalten werden k{\"o}nnen. Wir untersuchen Technologien, welche sich diesen Fragestellungen widmen, und diskutieren, ob und wie sie in der Cloud sowie f{\"u}r Simulationen einsetzbar sind. Weiterhin skizzieren wir wichtige zuk{\"u}nftige Forschungsthemen.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-52&engl=1}
}
@inproceedings {INPROC-2014-48,
   author = {Vasilios Andrikopoulos and Anja Reuter and Santiago G{\'o}mez S{\'a}ez and Frank Leymann},
   title = {{A GENTL Approach for Cloud Application Topologies}},
   booktitle = {Proceedings of the Third European Conference on Service-Oriented and Cloud Computing (ESOCC 2014)},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science (LNCS)},
   pages = {1--11},
   type = {Conference Paper},
   month = {September},
   year = {2014},
   keywords = {application topology language; annotation schemes; application distribution; cloud migration},
   language = {English},
   cr-category = {D.2.2 Software Engineering Design Tools and Techniques,     D.2.7 Software Engineering Distribution, Maintenance, and Enhancement,     H.4.2 Information Systems Applications Types of Systems},
   contact = {vasilios.andrikopoulos@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The availability of an increasing number of cloud offerings allows for innovative solutions in designing applications for the cloud and in adapting existing ones for this environment. An important ingredient in identifying the optimal distribution of an application in the cloud, potentially across offerings and providers, is a robust topology model that can be used for the automated deployment and management of the application. In order to support this process, in this work we present an application topology language aimed for cloud applications that is generic enough to allow the mapping from other existing languages and comes with a powerful annotation mechanism already built-in. We discuss its supporting environment that we developed and show how it can be used in practice to assist application designers.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-48&engl=1}
}
@inproceedings {INPROC-2014-47,
   author = {Vasilios Andrikopoulos and Alexander Darsow and Dimka Karastoyanova and Frank Leymann},
   title = {{CloudDSF - The Cloud Decision Support Framework for Application Migration}},
   booktitle = {Proceedings of the Third European Conference on Service-Oriented and Cloud Computing (ESOCC 2014)},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science (LNCS)},
   pages = {1--15},
   type = {Conference Paper},
   month = {September},
   year = {2014},
   keywords = {application migration; decision support; decision visualization},
   language = {English},
   cr-category = {D.2.7 Software Engineering Distribution, Maintenance, and Enhancement,     D.2.11 Software Engineering Software Architectures,     H.3.4 Information Storage and Retrieval Systems and Software,     H.3.5 Online Information Services,     H.4.2 Information Systems Applications Types of Systems},
   contact = {vasilios.andrikopoulos@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Migrating existing applications to cloud solutions is a multi-dimensional problem that spans beyond technical issues and into the financial, security and organizational domains. The existing works in the field form a picture of a maturing but still incomplete research area, requiring the introduction of comprehensive solutions for the migration of enterprise systems and applications to cloud solutions. As part of this effort, in this work we focus on supporting decision makers in evaluating the need for migration, and guiding them along the decisions that need to be made before the actual migration process. For this purpose we build on existing work to provide an elaborated decision support framework that is available as a Web application. We discuss the evaluation of the framework by experts, identify its deficiencies and outline our future steps.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-47&engl=1}
}
@inproceedings {INPROC-2014-46,
   author = {Johannes Wettinger and Uwe Breitenb{\"u}cher and Frank Leymann},
   title = {{DevOpSlang - Bridging the Gap Between Development and Operations}},
   booktitle = {Proceedings of the 3rd European Conference on Service-Oriented and Cloud Computing (ESOCC 2014)},
   publisher = {Springer-Verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {108--122},
   type = {Conference Paper},
   month = {September},
   year = {2014},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures,     C.2.4 Distributed Systems},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {DevOps is an emerging paradigm to eliminate the split and barrier between developers and operations personnel that traditionally exists in many enterprises today. The main promise of DevOps is to enable continuous delivery of software in order to enable fast and frequent releases. This enables quick responses to changing requirements of customers and thus may be a critical competitive advantage. In this work we propose a language called DevOpSlang in conjunction with a methodology to implement DevOps as an efficient means for collaboration and automation purposes. Efficient collaboration and automation are the key enablers to implement continuous delivery and thus to react to changing customer requirements quickly.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-46&engl=1}
}
@inproceedings {INPROC-2014-45,
   author = {Santiago G{\'o}mez S{\'a}ez and Vasilios Andrikopoulos and Frank Leymann},
   title = {{Performance-aware Application Distribution in the Cloud}},
   booktitle = {Proceedings of the Workshop on Enterprise Architekturen mit Big Data \& Cloud (EABDC 2014)},
   publisher = {Gesellschaft f{\"u}r Informatik e.V. (GI)},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--9},
   type = {Workshop Paper},
   month = {September},
   year = {2014},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     D.2.8 Software Engineering Metrics},
   contact = {Santiago G{\'o}mez S{\'a}ez: santiago.gomez-saez@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The emergence of Cloud computing and the improvement of resource management techniques have contributed to an increase in the number of application developers that are strong supporters of partially or completely migrating their application to a highly scalable and pay-per-use infrastructure. In this work in progress paper we begin the analysis on how to optimally distribute the application layers in the Cloud in order to adapt its topology to handle oscillating over time workloads. More specifically, through an empirical workload analysis and characterization we present our initial evaluation of an application persistence layer's performance under different deployment scenarios.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-45&engl=1}
}
@inproceedings {INPROC-2014-44,
   author = {Santiago G{\'o}mez S{\'a}ez and Vasilios Andrikopoulos and Florian Wessling and Clarissa Cassales Marquezan},
   title = {{Cloud Adaptation \& Application (Re-)Distribution: Bridging the two Perspectives}},
   booktitle = {Proceedings of the First International Workshop on Engineering Cloud Applications \& Services (EnCASE 2014)},
   publisher = {IEEE Computer Society Press},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {163--172},
   type = {Workshop Paper},
   month = {September},
   year = {2014},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures,     C.2.4 Distributed Systems},
   contact = {Santiago G{\'o}mez S{\'a}ez: santiago.gomez-saez@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Cloud developers have to make several decisions when running their application in a cloud environment that may lead to conflicting objectives, inefficient deployment, and inappropriate or not existing adaptation strategies. Proper decision-support tools and processes are therefore needed to make cloud developers aware of the issues that need to be considered when deploying and running applications in the Cloud. Current decision support tools for cloud developers do not provide a structured and organized process in which the cloud developers can systematically check their choices when planning the deployment, execution, and adaptation of applications in the Cloud. In this paper, we combine two previous works and introduce an approach for identifying the options for (re-)deploying application in cloud providers infrastructures and the possible strategies of adaptation that can be used by the deployed application at runtime. The key contribution is a support process that synthesizes the two approaches. We also describe a case study where our support process is applied and we indicate the alternatives for application (re-)deployment and adaptation.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-44&engl=1}
}
@inproceedings {INPROC-2014-42,
   author = {Michael Hahn and Dimka Karastoyanova},
   title = {{Configurable and Collaborative Scientific Workflows}},
   booktitle = {Workshop on Simulation Technology: Systems for Data Intensive Simulations (SimTech(at)GI) in Conjunction with INFORMATIK 2014},
   publisher = {Gesellschaft f{\"u}r Informatik e.V. (GI)},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Informatics (LNI)},
   volume = {P-232},
   pages = {125--136},
   type = {Workshop Paper},
   month = {September},
   year = {2014},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   contact = {Michael Hahn: michael.hahn@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The use of workflows to support and realize computer simulations, experiments and calculations is well-accepted in the e-Science domain. The different tasks and the parameters of the simulation are therefore specified in workflow models. Scientists typically work in a trial-and-error manner which means they do not know how the final workflow of a simulation has to look like. Therefore, they use a maybe insufficient workflow model as a basis and try to improve this model over multiple iterations to get a better approximation to the problem to solve. So in each iteration multiple trials are based on different variants of the same workflow model. Towards the goal of building variants of workflow models and enabling the reuse of existing scientific workflows in a controlled and well-defined manner, in this paper, we identify how configurable workflow models will support scientists to customize existing workflow models by their configuration. Therefore, we introduce possible configuration options for scientific workflows and how scientists can specify them. Furthermore, we show how configurable workflow models are a first step towards enabling the collaboration among scientists in creating scientific workflows.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-42&engl=1}
}
@inproceedings {INPROC-2014-41,
   author = {Alexander Nowak and Uwe Breitenb{\"u}cher and Frank Leymann},
   title = {{Automating Green Patterns to Compensate CO2 Emissions of Cloud-based Business Processes}},
   booktitle = {Proceedings of ADVCOMP 2014},
   editor = {IARIA Xpert Publishing Services},
   publisher = {IARIA},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {August},
   year = {2014},
   keywords = {Business Process Patterns; Management Automation; Cloud Computing; Infrastructure as a Service},
   language = {English},
   cr-category = {D.2.13 Software Engineering Reusable Software,     H.4.1 Office Automation},
   ee = {http://thinkmind.org/index.php?view=article&articleid=advcomp_2014_7_20_20077},
   contact = {alexander.nowak@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The usefulness of patterns to optimize the environmental impact of business processes and their infrastructure has already been described in literature. However, due to the abstract description of pattern solutions, the individual application of patterns has to be done manually which is time consuming, complex, and error-prone. In this work, we show how the Green Compensation pattern can be applied automatically to different individual Cloud-based business processes in order to lower the negative environmental impact of the employed Virtual Machines without any manual effort. We show how our Management Planlet Framework can be used to implement this concrete refined pattern solution in a reusable way.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-41&engl=1}
}
@inproceedings {INPROC-2014-40,
   author = {Andreas Wei{\ss} and Dimka Karastoyanova and David Molnar and Siegfried Schmauder},
   title = {{Coupling of Existing Simulations using Bottom-up Modeling of Choreographies}},
   booktitle = {Workshop on Simulation Technology: Systems for Data Intensive Simulations (SimTech\&\#64;GI) in Conjunction with INFORMATIK 2014},
   publisher = {Gesellschaft f{\"u}r Informatik e.V. (GI)},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {101--112},
   type = {Workshop Paper},
   month = {September},
   year = {2014},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {As a contribution for eScience, we discuss the bottom-up derivation of scientific choreography models from existing simulation workflows interconnected as a multi-scale and multi-field simulation. Starting from a motivating scenario of only implicitly coupled simulation workflows for the studying of thermal aging of iron-copper alloys, we present a choreography life cycle supporting the bottom-up derivation of choreography models and the propagation of changes to the underlying simulation workflows in a round-trip manner. Furthermore, we discuss several distinct starting points for the derivation, namely explicitly and implicitly connected simulation workflow models and already running simulation workflow instances.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-40&engl=1}
}
@inproceedings {INPROC-2014-39,
   author = {Andreas Wei{\ss} and Dimka Karastoyanova},
   title = {{A Life Cycle for Coupled Multi-Scale, Multi-Field Experiments Realized through Choreographies}},
   booktitle = {Proceedings of the 18th IEEE International EDOC Conference (EDOC 2014)},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {234--241},
   type = {Conference Paper},
   month = {September},
   year = {2014},
   doi = {10.1109/EDOC.2014.39},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Current systems for enacting scientific experiments, and in particular simulation workflows, do not support multi-scale and multi-field problems if they are not coupled on the level of the mathematical model. We present a life cycle that utilizes the notion of choreographies to enable the trial-and-error modeling and execution of multi-scale and/or multi-field simulations. The life cycle exhibits two views reflecting the characteristics of modeling and execution in a top-down and bottom-up manner. It defines techniques for composing data-intensive, scientific workflows in more complex simulations in a generic, domain-independent way, and thus provides scientists with means for collaborative and integrated data management based on the workflow paradigm.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-39&engl=1}
}
@inproceedings {INPROC-2014-38,
   author = {Johannes Wettinger and Katharina G{\"o}rlach and Frank Leymann},
   title = {{Deployment Aggregates - A Generic Deployment Automation Approach for Applications Operated in the Cloud}},
   booktitle = {Proceedings of the 18th International Enterprise Distributed Object Computing Conference Workshops and Demonstrations (International Workshop on Engineering Cloud Applications \& Services, EnCASE 2014)},
   publisher = {IEEE Computer Society Press},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {173--180},
   type = {Workshop Paper},
   month = {September},
   year = {2014},
   doi = {10.1109/EDOCW.2014.34},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures,     C.2.4 Distributed Systems},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {One of the most essential requirements to make use of the benefits of Cloud computing is fully automated provisioning and deployment of applications including all related resources. This leads to crucial cost reductions when deploying and operating applications in the Cloud because manual processes are slow, error-prone, and thus costly. Both Cloud providers and the open-source community provide a huge variety of tools, APIs, domain-specific languages, and reusable artifacts to implement deployment automation. However, the meta-models behind these approaches are diverse. This diversity makes it challenging to combine different approaches, avoiding vendor lock-in and tooling lock-in. In this work we propose deployment aggregates as a generic means to use and orchestrate different kinds of deployment approaches. We define a generic meta-model and show its relation to existing meta-models in the domain of deployment automation. Moreover, we discuss how existing artifacts can be used as deployment aggregates as a result of transformation and enrichment.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-38&engl=1}
}
@inproceedings {INPROC-2014-37,
   author = {Michael Falkenthal and Johanna Barzen and Uwe Breitenb{\"u}cher and Christoph Fehling and Frank Leymann},
   title = {{From Pattern Languages to Solution Implementations}},
   booktitle = {Proceedings of the Sixth International Conferences on Pervasive Patterns and Applications (PATTERNS 2014)},
   publisher = {Xpert Publishing Services},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {12--21},
   type = {Conference Paper},
   month = {May},
   year = {2014},
   isbn = {978-1-61208-343-8},
   keywords = {Pattern; Pattern Languages; Pattern-based Solution; Pattern Application; Cloud Computing Patterns},
   language = {English},
   cr-category = {C.0 Computer Systems Organization, General,     C.2.4 Distributed Systems,     D.2.2 Software Engineering Design Tools and Techniques,     D.2.3 Software Engineering Coding Tools and Techniques,     D.2.7 Software Engineering Distribution, Maintenance, and Enhancement},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Patterns are a well-known and often used concept in the domain of computer science. They document proven solutions to recurring problems in a specific context and in a generic way. So patterns are applicable in a multiplicity of specific use cases. However, since the concept of patterns aims at generalization and abstraction of solution knowledge, it is difficult to apply solutions provided by patterns to specific use cases, as the required knowledge about refinement and the manual effort that has to be spent is immense. Therefore, we introduce the concept of Solution Implementations, which are directly associated to patterns to efficiently support elaboration of concrete pattern implementations. We show how Solution Implementations can be aggregated to solve problems that require the application of multiple patterns at once. We validate the presented approach in the domain of cloud application architecture and cloud application management and show the feasibility of our approach with a prototype.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-37&engl=1}
}
@inproceedings {INPROC-2014-36,
   author = {Uwe Breitenb{\"u}cher and Tobias Binz and Oliver Kopp and Frank Leymann and Matthias Wieland},
   title = {{Context-aware Cloud Application Management}},
   booktitle = {Proceedings of the 4th International Conference on Cloud Computing and Services Science (CLOSER 2014)},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {499--509},
   type = {Conference Paper},
   month = {April},
   year = {2014},
   keywords = {Application Management; Context; Automation; Cloud Computing},
   language = {English},
   cr-category = {K.6 Management of Computing and Information Systems},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The automation of application management is one of the most important issues in Cloud Computing. However, the steadily increasing number of different services and software components employed in composite Cloud applications leads to a higher risk of unexpected side effects when different technologies work together that bring their own proprietary management APIs. Due to unknown dependencies and the increasing diversity and heterogeneity of employed technologies, even small management tasks on single components may compromise the whole application functionality for reasons that are neither expected nor obvious to non-experts. In this paper, we tackle these issues by introducing a method that enables detecting and correcting unintended effects of management tasks in advance by analyzing the context in which tasks are executed. We validate the method practically and show how context-aware expert management knowledge can be applied fully automatically to running Cloud applications.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-36&engl=1}
}
@inproceedings {INPROC-2014-35,
   author = {Uwe Breitenb{\"u}cher and Tobias Binz and Oliver Kopp and Frank Leymann},
   title = {{Automating Cloud Application Management Using Management Idioms}},
   booktitle = {Proceedings of the Sixth International Conferences on Pervasive Patterns and Applications (PATTERNS 2014)},
   publisher = {Xpert Publishing Services},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {60--69},
   type = {Conference Paper},
   month = {May},
   year = {2014},
   isbn = {978-1-61208-343-8},
   keywords = {Application Management; Automation; Patterns; Idioms; Cloud Computing},
   language = {English},
   cr-category = {D.2.7 Software Engineering Distribution, Maintenance, and Enhancement,     D.2.9 Software Engineering Management,     K.6 Management of Computing and Information Systems,     K.6.3 Software Management},
   ee = {http://thinkmind.org/index.php?view=article&articleid=patterns_2014_2_40_70038},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Patterns are a well-established concept to document generic solutions for recurring problems in an abstract manner. Especially in Information Technology (IT), many pattern languages exist that ease creating application architectures, designs, and management processes. Their generic nature provides a powerful means to describe knowledge in an abstract fashion that can be reused and refined for concrete use cases. However, the required manual refinement currently prevents applying the concept of patterns efficiently in the domain of Cloud Application Management as automation is one of the most important requirements in Cloud Computing. This paper presents an approach that enables automating both (i) the refinement of management patterns for individual use cases and (ii) the execution of the refined solutions: we introduce Automated Management Idioms to refine patterns automatically and extend an existing management framework to generate executable management workflows based on these refinements. We validate the presented approach by a prototypical implementation to prove its technical feasibility and evaluate its extensibility, standards compliance, and complexity.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-35&engl=1}
}
@inproceedings {INPROC-2014-34,
   author = {Karolina Vukojevic-Haupt and Florian Haupt and Dimka Karastoyanova and Frank Leymann},
   title = {{Service Selection for On-demand Provisioned Services}},
   booktitle = {Proceedings of the 18th IEEE International EDOC Conference (EDOC 2014)},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {120--127},
   type = {Conference Paper},
   month = {September},
   year = {2014},
   doi = {10.1109/EDOC.2014.25},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Service selection is an important concept in service oriented architectures that enables the dynamic binding of services based on functional and non-functional requirements. The introduction of the concept of on-demand provisioned services significantly changes the nature of services and as a consequence the traditional service selection process does not fit anymore. Existing approaches for service selection rely on the always on semantic of services, an assumption that is not valid for on-demand provisioned services. We tackle this problem by adapting the traditional service selection process and by defining an additional step covering the changes introduced by the concept of on-demand provisioning. Our solution comprises an extended architecture for on-demand provisioning, a metamodel for a service registry and a detailed definition and discussion of the adapted and extended service selection process. The work presented in this paper allows keeping the advantages of dynamic service binding at runtime and combining them with the advantages of Cloud computing exploited through the concept of on-demand provisioning.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-34&engl=1}
}
@inproceedings {INPROC-2014-33,
   author = {Florian Haupt and Markus Fischer and Dimka Karastoyanova and Frank Leymann and Karolina Vukojevic-Haupt},
   title = {{Service Composition for REST}},
   booktitle = {Proceedings of the 18th IEEE International EDOC Conference (EDOC 2014)},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {110--119},
   type = {Conference Paper},
   month = {September},
   year = {2014},
   issn = {1541-7719},
   doi = {10.1109/EDOC.2014.24},
   keywords = {Service Composition; REST; BPEL},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures},
   contact = {florian.haupt@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {One of the key strengths of service oriented architectures, the concept of service composition to reuse and combine existing services in order to achieve new and superior functionality, promises similar advantages when applied to resources oriented architectures. The challenge in this context is how to realize service composition in compliance with the constraints defined by the REST architectural style and how to realize it in a way that it can be integrated to and benefit from existing service composition solutions. Existing approaches to REST service composition are mostly bound to the HTTP protocol and often lack a systematic methodology and a mature and standards based realization approach. In our work, we follow a comprehensible methodology by deriving the key requirements for REST service composition directly from the REST constraints and then mapping these requirements to a standard compliant extension of the BPEL composition language. We performed a general requirements analysis for REST service composition, defined a meta model for a corresponding BPEL extension, realized this extension prototypically and validated it based on a real world use case from the eScience domain. Our work provides a general methodology to enable REST service composition as well as a realization approach that enables the combined composition of WSDL and REST services in a mature and robust way.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-33&engl=1}
}
@inproceedings {INPROC-2014-30,
   author = {Vasilios Andrikopoulos and Anja Reuter and Xiu Mingzhu and Frank Leymann},
   title = {{Design Support for Cost-efficient Application Distribution in the Cloud}},
   booktitle = {Proceedings of the 7th IEEE International Conference on Cloud Computing (CLOUD 2014)},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--8},
   type = {Conference Paper},
   month = {June},
   year = {2014},
   keywords = {Design Support; Provider Selection; Cost Calculation; Topology Modeling},
   language = {English},
   cr-category = {D.2.2 Software Engineering Design Tools and Techniques,     D.2.7 Software Engineering Distribution, Maintenance, and Enhancement,     H.4.2 Information Systems Applications Types of Systems},
   contact = {vasilios.andrikopoulos@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Application designers are faced with a series of design decisions when considering the number of available cloud services that can be used nowadays to host one or more parts of the application. Each one of these services comes with a different pricing model, which results in additional complexity when trying to identify the most cost-efficient solution. Toward this goal, in this work we present our proposal for a design support process that covers both the migration of existing applications and the (re)design of new ones specifically for the cloud. Furthermore, we also discuss an architecture for the realization of this process, as well as our implementation of this architecture.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-30&engl=1}
}
@inproceedings {INPROC-2014-27,
   author = {Santiago G{\'o}mez S{\'a}ez and Vasilios Andrikopoulos and Frank Leymann and Steve Strauch},
   title = {{Towards Dynamic Application Distribution Support for Performance Optimization in the Cloud}},
   booktitle = {Proceedings of the 7th IEEE International Conference on Cloud Computing (IEEE CLOUD 2014); Alaska, USA, June 27 - July 2, 2014},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {248--255},
   type = {Conference Paper},
   month = {June},
   year = {2014},
   keywords = {Synthetic Workload; Benchmark; Application Distribution; Application Deployment; Relational Database; TPC; Database-as-a-Service (DBaaS)},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures,     C.2.4 Distributed Systems,     D.2.8 Software Engineering Metrics},
   contact = {Santiago G{\'o}mez S{\'a}ez: gomez-saez@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The Cloud computing paradigm emerged by establishing new resources provisioning and consumption models. Together with the improvement of resource management techniques, these models have contributed to an increase in the number of application developers that are strong supporters of partially or completely migrating their application to a highly scalable and pay-per-use infrastructure. In this paper we derive a set of functional and non-functional requirements and propose a process-based approach to support the optimal distribution of an application in the Cloud in order to handle fluctuating over time workloads. Using the TPC-H workload as the basis, and by means of empirical workload analysis and characterization, we evaluate the application persistence layer's performance under different deployment scenarios using generated workloads with particular behavior characteristics.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-27&engl=1}
}
@inproceedings {INPROC-2014-25,
   author = {Uwe Breitenb{\"u}cher and Tobias Binz and Oliver Kopp and Frank Leymann},
   title = {{Vinothek - A Self-Service Portal for TOSCA}},
   booktitle = {Proceedings of the 6th Central-European Workshop on Services and their Composition (ZEUS 2014)},
   editor = {Nico Herzberg and Matthias Kunze},
   publisher = {CEUR-WS.org},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {CEUR Workshop Proceedings},
   volume = {1140},
   pages = {69--72},
   type = {Demonstration},
   month = {March},
   year = {2014},
   issn = {1613-0073},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://ceur-ws.org/Vol-1140/,     http://www.zeus-workshop.eu/},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The TOSCA standard provides a means to describe Cloud applications and their management in a portable way. TOSCA-based applications can be deployed on various standard-compliant TOSCA Runtimes. Vinothek is a Web-based Self-Service Portal that hides the technical details of TOSCA Runtimes and provides end users a simple graphical interface to provision Cloud applications on demand. This demonstration shows how Vinothek supports automated provisioning of applications and how it facilitates integrating TOSCA Runtimes.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-25&engl=1}
}
@inproceedings {INPROC-2014-24,
   author = {Florian Haupt and Frank Leymann and Alexander Nowak and Sebastian Wagner},
   title = {{Lego4TOSCA: Composable Building Blocks for Cloud Applications}},
   booktitle = {Proceedings of the 7th IEEE International Conference on Cloud Computing (CLOUD 2014)},
   editor = {IEEE},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {160--167},
   type = {Conference Paper},
   month = {July},
   year = {2014},
   isbn = {978-1-4799-5062-1},
   doi = {10.1109/CLOUD.2014.31},
   keywords = {Cloud; TOSCA},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures},
   contact = {florian.haupt@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The Topology and Orchestration Specification for Cloud Applications (TOSCA) enables the description, provisioning, and management of complex cloud applications in a portable way. TOSCA, therefore, provides a comprehensive yet complex set of mechanisms that may hinder users from unleashing its power due to misusing or neglecting parts of those mechanisms. TOSCA has just been standardized and, although it seems to be highly adopted in industry, there is a lack of systematic research of its features and capabilities. In this work we discuss the design of basic building blocks for cloud applications, called node types, and show how they can benefit from a deep integration with TOSCA. We developed a generic architecture for the realization of TOSCA node types, show an implementation of this architecture and validate it based on a sample cloud application. Our work gives an insight into the capabilities of TOSCA with respect to enable the creation of portable cloud services based on a set of composable building blocks.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-24&engl=1}
}
@inproceedings {INPROC-2014-23,
   author = {Florian Haupt and Dimka Karastoyanova and Frank Leymann and Benjamin Schroth},
   title = {{A Model-Driven Approach for REST Compliant Services}},
   booktitle = {Web Services (ICWS), 2014 IEEE International Conference on},
   editor = {IEEE},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {129--136},
   type = {Conference Paper},
   month = {July},
   year = {2014},
   isbn = {978-1-4799-5053-9},
   doi = {10.1109/ICWS.2014.30},
   keywords = {REST; MDSD},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures},
   contact = {florian.haupt@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The design of applications that comply to the REST architectural style requires observing a given set of architectural constraints. Following these constraints and therefore designing REST compliant applications is a non-trivial task often not fulfilled properly. There exist several approaches for the modeling and formal description of REST applications, but most of them do not pay any attention to how these approaches can support or even force REST compliance. In this paper we propose a model driven approach for modeling REST services. We introduce a multi layered model which enables (partially) enforcing REST compliance by separating different concerns through separate models. We contribute a multi layered meta-model for REST applications, discuss the connection to REST compliance and show an implementation of our approach based on the proposed meta-model and method. As a result our approach provides a holistic method for the design and realization of REST applications exhibiting the desired level of compliance to the constraints of the REST architectural style.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-23&engl=1}
}
@inproceedings {INPROC-2014-22,
   author = {Johannes Wettinger and Tobias Binz and Uwe Breitenb{\"u}cher and Oliver Kopp and Frank Leymann and Michael Zimmermann},
   title = {{Unified Invocation of Scripts and Services for Provisioning, Deployment, and Management of Cloud Applications Based on TOSCA}},
   booktitle = {Proceedings of the 4th International Conference on Cloud Computing and Services Science (CLOSER 2014)},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {559--568},
   type = {Conference Paper},
   month = {April},
   year = {2014},
   language = {English},
   cr-category = {K.6 Management of Computing and Information Systems,     C.2.4 Distributed Systems},
   contact = {E-mail: johannes.wettinger@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {There are several script-centric approaches, APIs, and tools available to implement automated provisioning, deployment, and management of applications in the Cloud. The automation of all these aspects is key for reducing costs. However, most of these approaches are script-centric and provide proprietary solutions employing different invocation mechanisms, interfaces, and state models. Moreover, most Cloud providers offer proprietary Web services or APIs to be used for provisioning and management purposes. Consequently, it is hard to create deployment and management plans integrating several of these approaches. The goal of our work is to come up with an approach for unified invocation of scripts and services without handling each proprietary interface separately. A prototype realizes the presented approach in a standards-based manner using the Topology and Orchestration Specification for Cloud Applications (TOSCA).},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-22&engl=1}
}
@inproceedings {INPROC-2014-21,
   author = {Uwe Breitenb{\"u}cher and Tobias Binz and K{\'a}lm{\'a}n K{\'e}pes and Oliver Kopp and Frank Leymann and Johannes Wettinger},
   title = {{Combining Declarative and Imperative Cloud Application Provisioning based on TOSCA}},
   booktitle = {Proceedings of the IEEE International Conference on Cloud Engineering (IC2E)},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {87--96},
   type = {Conference Paper},
   month = {March},
   year = {2014},
   doi = {10.1109/IC2E.2014.56},
   language = {English},
   cr-category = {K.6 Management of Computing and Information Systems},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The automation of application provisioning is one of the most important issues in Cloud Computing. The Topology and Orchestration Specification for Cloud Applications (TOSCA) supports automating provisioning by two different flavors: (i) declarative processing is based on interpreting application topology models by a runtime that infers provisioning logic whereas (ii) imperative processing employs provisioning plans that explicitly describe the provisioning tasks to be executed. Both flavors come with benefits and drawbacks. This paper presents a means to combine both flavors to resolve drawbacks and to profit from benefits of both worlds: we propose a standards-based approach to generate provisioning plans based on TOSCA topology models. These provisioning plans are workflows that can be executed fully automatically and may be customized by application developers after generation. We prove the technical feasibility of the approach by an end-to-end open source toolchain and evaluate its extensibility, performance, and complexity.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-21&engl=1}
}
@inproceedings {INPROC-2014-20,
   author = {Vasilios Andrikopoulos and Marina Bitsaki and Antonio Bucchiarone and Santiago G{\'o}mez S{\'a}ez and Dimka Karastoyanova and Frank Leymann and Christos Nikolaou and Marco Pistore},
   title = {{A Game Theoretic Approach for Managing Multi-Modal Urban Mobility Systems}},
   booktitle = {Proceedings of the 5th International Conference on Applied Human Factors and Ergonomics (AHFE 2014)},
   address = {Krak{\'o}w, Poland},
   publisher = {CRC Press/Taylor \& Francis},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {July},
   year = {2014},
   language = {English},
   cr-category = {D.2.0 Software Engineering General,     G.4 Mathematical Software,     I.1.2 Symbolic and Algebraic Manipulation Algorithms,     I.2.11 Distributed Artificial Intelligence},
   contact = {Vasilios Andrikopoulos: andrikopoulos@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Collective adaptive systems provide secure and robust collaboration between heterogeneous entities such as humans and computer systems. Such entities have potentially conflicting goals that attempt to satisfy by interacting with each other. Understanding and analyzing their behavior and evolution requires technical, social and economic aspects of modeling. In this paper, we develop a new design principle to describe an integrated and multimodal urban mobility system and model the interactions of various entities by means of game theoretic techniques.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-20&engl=1}
}
@inproceedings {INPROC-2014-19,
   author = {Vasilios Andrikopoulos and Santiago G{\'o}mez S{\'a}ez and Frank Leymann and Johannes Wettinger},
   title = {{Optimal Distribution of Applications in the Cloud}},
   booktitle = {Proceedings of the 26th Conference on Advanced Information Systems Engineering (CAiSE 2014)},
   editor = {Matthias Jarke and John Mylopoulos and Christoph Quix},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science (LNCS)},
   pages = {1--15},
   type = {Conference Paper},
   month = {June},
   year = {2014},
   keywords = {application topology; distribution optimization; cloud computing; operational expenses},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures,     C.2.4 Distributed Systems},
   contact = {vasilios.andrikopoulos@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In an environment of constant change and variation driven by competition and innovation, a software service can rarely remain stable. Being able to manage and control the evolution of services is therefore an important goal for the Service-Oriented paradigm. This work extends existing and widely-adopted theories from software engineering, programming languages, service oriented computing and other related fields to provide the fundamental ingredients required to guarantee that spurious results and inconsistencies that may occur due to uncontrolled service changes are avoided. The presented work provides a unifying theoretical framework for controlling the evolution of services that deals with structural, behavioral and QoS level-induced service changes in a type-safe manner. The goal of the work is to ensure correct version transitions so that previous and future clients can use a service in a consistent manner.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-19&engl=1}
}
@inproceedings {INPROC-2014-18,
   author = {Vasilios Andrikopoulos},
   title = {{On the (Compatible) Evolution of Services}},
   booktitle = {Software Engineering 2014},
   editor = {Wilhelm Hasselbring and Nils Christian Ehmke},
   publisher = {Gesellschaft f{\"u}r Informatik e.V. (GI)},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Series of the Gesellschaft f{\"u}r Informatik (GI)},
   volume = {P-227},
   pages = {55--56},
   type = {Conference Paper},
   month = {January},
   year = {2014},
   language = {English},
   cr-category = {D.2.7 Software Engineering Distribution, Maintenance, and Enhancement,     D.2.12 Software Engineering Interoperability,     F.4.0 Mathematical Logic and Formal Languages General},
   contact = {vasilios.andrikopoulos@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In an environment of constant change and variation driven by competition and innovation, a software service can rarely remain stable. Being able to manage and control the evolution of services is therefore an important goal for the Service-Oriented paradigm. This work extends existing and widely-adopted theories from software engineering, programming languages, service oriented computing and other related fields to provide the fundamental ingredients required to guarantee that spurious results and inconsistencies that may occur due to uncontrolled service changes are avoided. The presented work provides a unifying theoretical framework for controlling the evolution of services that deals with structural, behavioral and QoS level-induced service changes in a type-safe manner. The goal of the work is to ensure correct version transitions so that previous and future clients can use a service in a consistent manner.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-18&engl=1}
}
@inproceedings {INPROC-2014-17,
   author = {Sebastian Wagner and Oliver Kopp and Frank Leymann},
   title = {{Choreography-based Consolidation of Multi-Instance BPEL Processes}},
   booktitle = {Proceedings of the 4th International Conference on Cloud Computing and Services Science (CLOSER 2014);Barcelona, Spain, April 3-5, 2014.},
   editor = {SciTePress},
   address = {Barcelona},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--12},
   type = {Conference Paper},
   month = {April},
   year = {2014},
   keywords = {BPEL; Choreography; Process Consolidation; Multi-Instance Interactions},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   contact = {sebastian.wagner@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Interaction behavior between processes of different organizational units such as an enterprise and its suppliers can be modeled by choreographies. When organizations decide, for instance, to gain more control about their suppliers to minimize transaction costs, they may decide to insource these companies. This especially includes the integration of the partner processes into the organization’s processes. Existing works are able to merge single-instance BPEL process interactions where each process model is only instantiated once during choreography execution. However, there exist different interaction scenarios where one process interacts with several instances of another process and where the number of instances involved is not known at design time but determined during runtime of the choreography. In this work we investigate these interaction scenarios and extend the process consolidation approach in a way that we can emulate the multi-instance interaction scenarios in the merged process model.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-17&engl=1}
}
@inproceedings {INPROC-2014-13,
   author = {Marigianna Skouradaki and Dieter H. Roller and Cesare Pautasso and Frank Leymann},
   title = {{BPELanon: Anonymizing BPEL Processes}},
   booktitle = {Proceedings of the 6th Central European Workshop on Services and their Composition (ZEUS 2014), Potsdam Germany, February 20-21, 2014},
   editor = {Oliver Kopp and Niels Lohmann},
   publisher = {CEUR-WS.org},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {9--15},
   type = {Workshop Paper},
   month = {February},
   year = {2014},
   keywords = {Anonymization; BPEL; Workflows; Business Processes},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   contact = {marigianna.skouradaki@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {We are currently developing a performance benchmark for Workflow Management System. As a first activity we are collecting real-world processes. However, to protect their competitive advantage, some companies are not willing to share their corporate assets. This work's objective is to propose a method (``BPELanon'') for BPEL process anonymization in order to deal with the problem. The method transforms a process to preserve its original structure and runtime behaviour, while completely anonymizing its business semantics. Anonymization is a complicated task that must meet the requirements we outline in this paper. Namely, we need to preserve the structural and executional information while anonymizing information such as namespaces, names (activity names, variable names, partner link names etc.), and XPATH expressions that may reveal proprietary information. Furthermore, the names contained in the anonymized process should be chosen carefully in order to avoid conflicts, preserve privacy, and file-readability. Multiple dependency relations among process artifacts raise the challenge of fulfilling the aforementioned requirements, as a unique change in a file potentially leads to a flow of changes to other related process artifacts.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-13&engl=1}
}
@inproceedings {INPROC-2014-12,
   author = {Alexander Nowak and Frank Leymann},
   title = {{Green Enterprise Patterns (to appear)}},
   booktitle = {Proceedings of the 20th Conference on Pattern Languages of Programs (PLoP), October 23-26, Allerton, IL, USA},
   publisher = {ACM},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--1},
   type = {Conference Paper},
   month = {January},
   year = {2014},
   keywords = {Management, Documentation, Design, Standardization, Environment, Business, Enterprise, Health of Environment, Business Design, Sustainability},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   contact = {alexander.nowak@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {To provide services and goods, enterprises are consuming and using various types of resources. The use of resources, especially the use of non-renewable resources or resources that originate certain pollution or waste, has an intrinsic impact to our environment. However, the health of our environment is crucial for life on earth. The patterns in this work, namely Integrated Green Business, Green Resource Providing, Green Service Communication and Green Service Selection, address different aspects of sustainability that may be considered when building enterprises with sustainability in mind.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-12&engl=1}
}
@inproceedings {INPROC-2014-11,
   author = {Vasilios Andrikopoulos and Marina Bitsaki and Santiago G{\'o}mez S{\'a}ez and Dimka Karastoyanova and Christos Nikolaou and Alina Psycharaki},
   title = {{Utility-based Decision Making in Collective Adaptive Systems}},
   booktitle = {Proceedings of the Fourth International Conference on Cloud Computing and Service Science (CLOSER'14)},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {308--314},
   type = {Conference Paper},
   month = {April},
   year = {2014},
   language = {English},
   cr-category = {D.2.0 Software Engineering General,     D.2.11 Software Engineering Software Architectures,     D.2.12 Software Engineering Interoperability},
   contact = {Vasilios Andrikopoulos: vasilios.andrikopoulos@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Large-scale systems comprising of multiple heterogeneous entities are directly influenced by the interactions of their participating entities. Such entities, both physical and virtual, attempt to satisfy their objectives by dynamically collaborating with each other, and thus forming collective adaptive systems. These systems are subject to the dynamicity of the entities' objectives, and to changes to the environment. In this work we focus on the latter, i.e. on providing the means for entities in such systems to model, monitor and evaluate their perceived utility by participating in the system. This allows for them to make informed decisions about their interactions with other entities in the system. For this purpose we propose a utility-based approach for decision making, as well as an architecture that allows for the support of this approach.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-11&engl=1}
}
@inproceedings {INPROC-2014-08,
   author = {Vasilios Andrikopoulos and Santiago G{\'o}mez S{\'a}ez and Dimka Karastoyanova and Andreas Wei{\ss}},
   title = {{Collaborative, Dynamic \& Complex Systems: Modeling, Provision \& Execution}},
   booktitle = {Proceedings of the Fourth International Conference on Cloud Computing and Service Science (CLOSER'14)},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {276--286},
   type = {Conference Paper},
   month = {April},
   year = {2014},
   language = {English},
   cr-category = {D.2.0 Software Engineering General,     D.2.11 Software Engineering Software Architectures,     D.2.12 Software Engineering Interoperability},
   contact = {Vasilios Andrikopoulos: andrikopoulos@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Service orientation has significantly facilitated the development of complex distributed systems spanning multiple organizations. However, different application areas approach such systems in domain-specific ways, focusing only on particular aspects relevant for their application types. As a result, we observe a very fragmented landscape of service-oriented systems, which does not enable collaboration across organizations. To address this concern, in this work we introduce the notion of Collaborative, Dynamic and Complex (CDC) systems and position them with respect to existing technologies. In addition, we present how CDC systems are modeled and the steps to provision and execute them. Furthermore, we contribute an architecture and prototypical implementation, which we evaluate by means of a case study in a Cloud-enabled context-aware pervasive application.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-08&engl=1}
}
@inproceedings {INPROC-2014-06,
   author = {Steve Strauch and Vasilios Andrikopoulos and Santiago G{\'o}mez S{\'a}ez and Frank Leymann},
   title = {{Transparent Access to Relational Databases in the Cloud Using a Multi-Tenant ESB}},
   booktitle = {Proceedings of the 4th International Conference on Cloud Computing and Service Science (CLOSER'14)},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {5--14},
   type = {Conference Paper},
   month = {April},
   year = {2014},
   keywords = {Data Access Layer; Relational Databases; Enterprise Service Bus (ESB); Multi-Tenancy},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     C.4 Performance of Systems,     D.2.11 Software Engineering Software Architectures,     H.2.0 Database Management General,     H.2.4 Database Management Systems},
   contact = {a href=``http://www.iaas.uni-stuttgart.de/institut/mitarbeiter/strauch''Steve Strauch/ a},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In the last years Cloud computing has become popular among IT organizations aiming to reduce their operational costs. Applications can be designed to run in the Cloud, or can be partially or completely migrated to it. Migrating the data layer of an application to the Cloud, however, implies that existing applications might need to be adapted in order to access their migrated to the Cloud databases. In this work we examine how we can use an existing ESB to enable transparent access to the relational data store running either in the Cloud or on-premise. The goal of our approach is to minimize the effort required to adapt the application. In particular, we discuss the requirements and prototype realization of a Cloud aware data access layer for transparent data access, using an existing open source and multi-tenant aware ESB as the basis. We then evaluate the performance of our proposed solution by considering different Cloud providers and using example data from an existing benchmark as application workload.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-06&engl=1}
}
@inproceedings {INPROC-2014-04,
   author = {Johanna Barzen and Frank Leymann},
   title = {{Kost{\"u}msprache als Mustersprache: Vom analytischen Wert Formaler Sprachen und Muster in den Filmwissenschaften}},
   booktitle = {Extended Abstract Digital Humanities im deutschsprachigen Raum (DHd 2014)},
   publisher = {DHd 2014},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--2},
   type = {Conference Paper},
   month = {January},
   year = {2014},
   keywords = {Kost{\"u}msprache; Costume Language; Mustersprache; Pattern Language; Vestimentary Communication; Empirical Film Analysis},
   language = {German},
   cr-category = {J.5 Arts and Humanities,     D.3.1 Programming Languages Formal Definitions and Theory},
   contact = {johanna.barzen@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In den Medienwissenschaften ist die Frage, wie Kostuemsprache im Film greifbar und verstehbar gemacht werden kann, ein Problem: Eine praezise Definition des Begriffs erweist sich als schwierig. Hier kann das Konzept einer Formalen Sprache aus der Informatik genutzt werden, um eine solche praezise Definition zu geben.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-04&engl=1}
}
@inproceedings {INPROC-2014-02,
   author = {Santiago G{\'o}mez S{\'a}ez and Vasilios Andrikopoulos and Frank Leymann and Steve Strauch},
   title = {{Evaluating Caching Strategies for Cloud Data Access using an Enterprise Service Bus}},
   booktitle = {Proceedings of the IEEE International Conference on Cloud Engineering (IEEE IC2E 2014)},
   address = {Boston, Massachusetts, USA},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {289--294},
   type = {Conference Paper},
   month = {March},
   year = {2014},
   keywords = {Multi-tenancy; Enterprise Service Bus (ESB); Cache; Relational Databases},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     H.3.4 Information Storage and Retrieval Systems and Software},
   contact = {E-Mail: santiago.gomez-saez@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Nowadays different Cloud services enable enterprises to migrate applications to the Cloud. An application can be partially migrated by replacing some of its components with Cloud services, or by migrating one or multiple of its layers to the Cloud. As a result, accessing application data stored off-premise requires mechanisms to mitigate the negative impact on Quality of Service (QoS), e.g. due to network latency. In this work, we propose and realize an approach for transparently accessing data migrated to the Cloud using a multi-tenant open source Enterprise Service Bus (ESB) as the basis. Furthermore, we enhance the ESB with QoS awareness by integrating it with an open source caching solution. For evaluation purposes we generate a representative application workload using data from the TPC-H benchmark. Based on this workload, we then evaluate the optimal caching strategy among multiple eviction algorithms when accessing relational databases located at different Cloud providers.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-02&engl=1}
}
@inproceedings {INPROC-2014-01,
   author = {Johannes Wettinger and Vasilios Andrikopoulos and Steve Strauch and Frank Leymann},
   title = {{Characterizing and Evaluating Different Deployment Approaches for Cloud Applications}},
   booktitle = {Proceedings of the IEEE International Conference on Cloud Engineering (IC2E 2014)},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {205--214},
   type = {Conference Paper},
   month = {March},
   year = {2014},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures,     K.6 Management of Computing and Information Systems},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Fully automated provisioning and deployment in order to reduce the costs for managing applications is one of the most essential requirements to make use of the benefits of Cloud computing. Several approaches and tools are available to automate the involved processes. The DevOps community, for example, provides tooling and artifacts to realize deployment automation on Infrastructure as a Service level in a mostly application-oriented manner. Platform as a Service frameworks are also available for the same purpose. In this paper we categorize and characterize available deployment approaches independently from the underlying technology used. For this purpose, we choose Web applications with different technology stacks and analyze their specific deployment requirements. Afterwards, we provision these applications using each of the identified types of deployment approaches in the Cloud. Finally, we discuss the evaluation results and derive recommendations which deployment approach to use based on the deployment requirements of an application.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2014-01&engl=1}
}
@inproceedings {INPROC-2013-61,
   author = {Falko Koetter and Monika Kochanowski and Thomas Renner and Christoph Fehling and Frank Leymann},
   title = {{Unifying Compliance Management in Adaptive Environments through Variability Descriptors (Short Paper)}},
   booktitle = {Proceedings of the 6th IEEE International Conference on Service Oriented Computing and Applications (SOCA)},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--8},
   type = {Conference Paper},
   month = {December},
   year = {2013},
   keywords = {Compliance, BPM, Adaptability, Variability},
   language = {English},
   cr-category = {C.0 Computer Systems Organization, General,     C.2.4 Distributed Systems,     D.2.2 Software Engineering Design Tools and Techniques,     D.2.7 Software Engineering Distribution, Maintenance, and Enhancement},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {When managing IT environments and designing business processes, compliance regulations add challenges. Especially considering adaptive environments in the context of a service-oriented architecture in combination with exploiting the advantages of cloud technologies, maintaining compliance is cumbersome. Measures have to be taken on many application levels - including business processes, IT architecture, and business management. Although a lot of work has been done on various approaches covering compliance on one or more of these levels, in large companies more than one approach is likely to be employed. However, a unified approach for supporting the compliance tasks - like introduction, maintenance, and especially adaptation - on different levels of business and IT is missing. This work introduces this unifying approach, which links compliance requirements to implementing technology using variable compliance descriptors in order to comprehensively support compliance tasks. The advantage of this approach is that the impact of compliance on these different levels is tracked, thus enabling change propagation from changes in compliance requirements to infrastructure and business process reconfiguration.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-61&engl=1}
}
@inproceedings {INPROC-2013-60,
   author = {Katharina G{\"o}rlach and Frank Leymann and Volker Claus},
   title = {{Unified Execution of Service Compositions}},
   booktitle = {Proceedings of the 6th IEEE International Conference on Service Oriented Computing \& Applications (SOCA 2013)},
   publisher = {IEEE Computer Society Conference Publishing Services},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {162--167},
   type = {Conference Paper},
   month = {December},
   year = {2013},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures,     D.3.1 Programming Languages Formal Definitions and Theory,     D.3.2 Programming Language Classifications,     F.4.2 Grammars and Other Rewriting Systems,     F.4.3 Formal Languages,     H.4.1 Office Automation},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2013-60/INPROC-2013-60.pdf},
   contact = {goerlach@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {This paper discusses the unification of service composition based on formal specifications. The approach aims for a unified execution of service compositions that can be modeled by various specification languages covering different modeling paradigms. The unification of service composition models is realized based on formal grammars whereas the unification of service composition execution is realized based on formal queued automata. The approach introduces a classification of context-sensitive grammars for determining an optimized automaton class for the execution of service compositions. Finally, a prototype providing transformations of various modeling languages to formal grammars as well as the grammar-based execution of service compositions is presented.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-60&engl=1}
}
@inproceedings {INPROC-2013-58,
   author = {Karolina Vukojevic-Haupt and Dimka Karastoyanova and Frank Leymann},
   title = {{On-demand Provisioning of Infrastructure, Middleware and Services for Simulation Workflows}},
   booktitle = {Proceedings of the 6th IEEE International Conference on Service Oriented Computing \& Applications (SOCA 2013), Kauai, USA, 16.-18.12.2013.},
   address = {Kauai, USA},
   publisher = {IEEE Press},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {91--98},
   type = {Conference Paper},
   month = {December},
   year = {2013},
   doi = {10.1109/SOCA.2013.21},
   keywords = {on-demand provisioning and deprovisioning; dynamic service deployment and provisioning; provisioning engine; bootware; simulation workflows; eScience; SOC; Cloud; TOSCA},
   language = {English},
   cr-category = {H.4.1 Office Automation,     C.2.4 Distributed Systems,     I.6.7 Simulation Support Systems},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2013-58/INPROC-2013-58.pdf},
   contact = {karolina.vukojevic@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Service orientation is a mainstream paradigm in business applications and gains even greater acceptance in the very active field of eScience. In SOC service binding strategies have been defined to specify the point in time a service can be discovered and selected for use, namely static binding, dynamic binding at deployment or at run time, and dynamic service deployment. The basic assumption in all these strategies is that the software stack and infrastructure necessary to execute the services are already available. While in service-based business applications this is typically a valid assumption in scientific applications it is often not the case. Therefore, in this work we introduce a new binding strategy for services we call on-demand provisioning which entails provisioning of the software stack necessary for the service and subsequent dynamic deployment of the service itself. Towards this goal, we also contribute a middleware architecture that enables the provisioning of the software stack – functionality unavailable in conventional service middlewares. We demonstrate the approach and the capabilities of the middleware and the current state of the implementation of our approach. For this purpose we use an example application from the field of eScience that comprises a scientific workflow management system for simulations.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-58&engl=1}
}
@inproceedings {INPROC-2013-56,
   author = {Steve Strauch and Vasilios Andrikopoulos and Bachmann Thomas and Dimka Karastoyanova and Stephan Passow and Karolina Vukojevic-Haupt},
   title = {{Decision Support for the Migration of the Application Database Layer to the Cloud}},
   booktitle = {Proceedings of the 5th IEEE International Conference on Cloud Computing Technology and Science (CloudCom'13)},
   publisher = {IEEE Computer Society Press},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {639--646},
   type = {Conference Paper},
   month = {December},
   year = {2013},
   doi = {10.1109/CloudCom.2013.90},
   keywords = {Data Migration; Decision Support; Database layer; Application Refactoring},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures,     H.3.4 Information Storage and Retrieval Systems and Software},
   contact = {a href=``http://www.iaas.uni-stuttgart.de/institut/mitarbeiter/strauch''Steve Strauch/ a},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Migrating an existing application to the Cloud is a complex and multi-dimensional problem requiring in many cases adapting the application in significant ways. Looking specifically into the database layer of the application, i.e. the aspect providing data persistence and manipulation capabilities, this involves dealing with differences in the granularity of interactions, refactoring of the application to cope with remote data sources, and addressing data confidentiality concerns. Toward this goal, in this work we present an application migration methodology which incorporates these aspects, and a decision support, application refactoring and data migration tool that assists application developers in realizing this methodology. For purposes of evaluating our proposal we present the results of a case study conducted in the context of an eScience project.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-56&engl=1}
}
@inproceedings {INPROC-2013-55,
   author = {Vasilios Andrikopoulos and Santiago G{\'o}mez S{\'a}ez and Dimka Karastoyanova and Andreas Wei{\ss}},
   title = {{Towards Collaborative, Dynamic \& Complex Systems}},
   booktitle = {Proceedings of the 6th International Conference on Service-Oriented Computing and Applications (SOCA'13)},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {IEEE Computer Society},
   pages = {1--5},
   type = {Conference Paper},
   month = {December},
   year = {2013},
   keywords = {collaborative, dynamic \& complex systems; service orchestration \& choreography; pervasive computing; service networks; context-awareness},
   language = {English},
   cr-category = {D.2.0 Software Engineering General,     D.2.11 Software Engineering Software Architectures,     D.2.12 Software Engineering Interoperability},
   contact = {vasilios.andrikopoulos@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Service orientation has significantly facilitated the development of complex distributed systems spanning multiple organizations. However, different application areas approach such systems in domain-specific ways, focusing on particular aspects relevant only for their application types. As a result, we observe a very fragmented landscape of service-oriented systems, which does not enable collaboration across organizations. To address this concern, in this work we introduce the notion of Collaborative, Dynamic and Complex (CDC) systems and position them with respect to existing technologies. In addition, we present how CDC systems are modeled and the steps to provision and execute them. We also contribute an architecture enabling CDC Systems with full life cycle coverage that allows for leveraging service-oriented and Cloud-related technologies.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-55&engl=1}
}
@inproceedings {INPROC-2013-54,
   author = {Vasilios Andrikopoulos and Antonio Bucchiarone and Santiago G{\'o}mez S{\'a}ez and Dimka Karastoyanova and Claudio Antares Mezzina},
   title = {{Towards Modeling and Execution of Collective Adaptive Systems}},
   booktitle = {Proceedings of the 9th International Workshop on Engineering Service-Oriented Applications (WESOA'13)},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--12},
   type = {Workshop Paper},
   month = {December},
   year = {2013},
   language = {English},
   cr-category = {D.2.0 Software Engineering General,     D.2.11 Software Engineering Software Architectures,     D.2.12 Software Engineering Interoperability},
   contact = {vasilios.andrikopoulos@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Collective Adaptive Systems comprise large numbers of heterogeneous entities that can join and leave the system at any time depending on their own objectives. In the scope of pervasive computing, both physical and virtual entities may exist, e.g., buses and their passengers using mobile devices, as well as city-wide traffic coordination systems. In this paper we introduce a novel conceptual framework that enables Collective Adaptive Systems based on well-founded and widely accepted paradigms and technologies like service orientation, distributed systems, context-aware computing and adaptation of composite systems. Toward achieving this goal, we also present an architecture that underpins the envisioned framework, discuss the current state of our implementation effort, and we outline the open issues and challenges in the field.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-54&engl=1}
}
@inproceedings {INPROC-2013-53,
   author = {Christoph Fehling and Frank Leymann and Stefan T. Ruehl and Marc Rudek and Stephan Verclas},
   title = {{Service Migration Patterns - Decision Support and Best Practices for the Migration of Existing Service-based Applications to Cloud Environments}},
   booktitle = {Proceedings of the 6th IEEE International Conference on Service Oriented Computing and Applications (SOCA)},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--8},
   type = {Conference Paper},
   month = {December},
   year = {2013},
   keywords = {SOA; cloud; migration; compliance},
   language = {English},
   cr-category = {C.0 Computer Systems Organization, General,     C.2.4 Distributed Systems,     D.2.2 Software Engineering Design Tools and Techniques,     D.2.3 Software Engineering Coding Tools and Techniques,     D.2.7 Software Engineering Distribution, Maintenance, and Enhancement},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In many ways cloud computing is an extension of the service-oriented computing (SOC) approach to create resilient and elastic hosting environments and applications. Service-oriented Architectures (SOA), thus, share many architectural properties with cloud environments and cloud applications, such as the distribution of application functionality among multiple application components (services) and their loosely coupled integration to form a distributed application. Existing service-based applications are, therefore, ideal candidates to be moved to cloud environments in order to benefit from the cloud properties, such as elasticity or pay-per-use pricing models. In order for such an application migration and the overall restructuring of an IT application landscape to be successful, decisions have to be made regarding (i) the portion of the application stack to be migrated and (ii) the process to follow during the migration in order to guarantee an acceptable service level to application users. In this paper, we present best practices how we addressed these challenges in form of service migration patterns as well as a methodology how these patterns should be applied during the migration of a service-based application or multiples thereof. Also, we present an implementation of the approach, which has been used to migrate a web-application stack from Amazon Web Services to the T-Systems cloud offering Dynamic Services for Infrastructure (DSI).},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-53&engl=1}
}
@inproceedings {INPROC-2013-50,
   author = {Tobias Binz and Uwe Breitenb{\"u}cher and Oliver Kopp and Frank Leymann},
   title = {{Automated Discovery and Maintenance of Enterprise Topology Graphs}},
   booktitle = {Proceedings of the 6th IEEE International Conference on Service Oriented Computing \& Applications (SOCA 2013)},
   publisher = {IEEE Computer Society Conference Publishing Services},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {126--134},
   type = {Conference Paper},
   month = {December},
   year = {2013},
   doi = {10.1109/SOCA.2013.29},
   keywords = {Discovery; Maintenance; Enterprise Topology Graph; Enterprise IT; Crawling},
   language = {English},
   cr-category = {K.6 Management of Computing and Information Systems,     D.2.12 Software Engineering Interoperability},
   contact = {a href=``http://www.iaas.uni-stuttgart.de/institut/mitarbeiter/binz''Tobias Binz/ a},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Enterprise Topology Graphs (ETGs) represent a snapshot of the complete enterprise IT, including all its applications, processes, services, components, and their dependencies. In the past, ETGs have been applied in analysis, optimization, and adaptation of enterprise IT. But how to discover and maintain a complete, accurate, fresh, and fine-grained Enterprise Topology Graph? Existing approaches either do not provide enough technical details or do not cover the complete scope of Enterprise Topology Graphs. Although existing tools are able to discover valuable information, there is no means for seamless integration. This paper proposes a plugin-based approach and extensible framework for automated discovery and maintenance of Enterprise Topology Graphs. The approach is able to integrate various kinds of tools and techniques into a unified model. We implemented the proposed approach in a prototype and applied it to different scenarios. Due to the vital role of discovery plugins in our approach, we support plugin development with a systematic testing method and discuss the lessons we learned. The results presented in this paper enable new ways of enterprise IT optimization, analysis, and adaptation. Furthermore, they unlock the full potential of past research, which previously required manual modeling of ETGs.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-50&engl=1}
}
@inproceedings {INPROC-2013-49,
   author = {Uwe Breitenb{\"u}cher and Tobias Binz and Oliver Kopp and Frank Leymann and Johannes Wettinger},
   title = {{Integrated Cloud Application Provisioning: Interconnecting Service-Centric and Script-Centric Management Technologies}},
   booktitle = {Proceedings of the 21st International Conference on Cooperative Information Systems (CoopIS 2013)},
   address = {Stuttgart},
   publisher = {Springer Berlin Heidelberg},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science},
   volume = {8185},
   pages = {130--148},
   type = {Conference Paper},
   month = {September},
   year = {2013},
   isbn = {978-3-642-41029-1},
   doi = {10.1007/978-3-642-41030-7_9},
   keywords = {Cloud Application Provisioning; Integration; Management Scripts; Management Services},
   language = {English},
   cr-category = {K.6 Management of Computing and Information Systems},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Modern Cloud applications employ a plethora of components and XaaS offerings that need to be configured during provisioning. Due to increased heterogeneity, complexity is growing and existing approaches reach their limits if multiple different provisioning and configuration technologies are involved. They are not able to integrate them in an automated, flexible, and customizable way. Especially combining proprietary management services with script-centric configuration management technologies is currently a major challenge. To enable automated provisioning of such applications, we introduce Generic Lifecycle Management Planlets that provide a means to combine custom provisioning logic with common provisioning tasks. We implemented planlets for provisioning and customization of components and XaaS offerings based on both SOAP and RESTful Web services as well as configuration management technologies such as Chef to show the feasibility of the approach. By using our approach, multiple technologies can be combined seamlessly.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-49&engl=1}
}
@inproceedings {INPROC-2013-48,
   author = {Uwe Breitenb{\"u}cher and Tobias Binz and Oliver Kopp and Frank Leymann and Matthias Wieland},
   title = {{Policy-Aware Provisioning of Cloud Applications}},
   booktitle = {SECURWARE 2013, The Seventh International Conference on Emerging Security Information, Systems and Technologies},
   publisher = {Xpert Publishing Services},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {86--95},
   type = {Conference Paper},
   month = {August},
   year = {2013},
   isbn = {978-1-61208-298-1},
   keywords = {Cloud Applications; Provisioning; Security; Policies},
   language = {English},
   cr-category = {K.6 Management of Computing and Information Systems},
   ee = {http://www.thinkmind.org/index.php?view=article&articleid=securware_2013_4_40_30149},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The automated provisioning of complex composite Cloud applications is a major issue and of vital importance in Cloud computing. It is key to enable Cloud properties such as pay-as-you-go pricing, on-demand self-service, and elasticity. The functional aspects of provisioning such as instantiating virtual machines or installing software components are covered by several technologies on different technical levels: some are targeted to a pretty high level such as Amazon’s Cloud Formation, some deal with deep technical issues based on scripts such as Chef or Puppet. However, the currently available solutions are tightly coupled to individual technologies without being able to consider non-functional security requirements in a non-proprietary and interoperable way. In this paper, we present a concept and framework extension enabling the integration of heterogeneous provisioning technologies under compliance with non-functional aspects defined by policies.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-48&engl=1}
}
@inproceedings {INPROC-2013-47,
   author = {Alexander Nowak and Frank Leymann},
   title = {{Green Business Process Patterns - Part II}},
   booktitle = {Proceedings of the 6th IEEE International Conference on Service Oriented Computing \& Applications (SOCA 2013)},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {December},
   year = {2013},
   keywords = {Green Business Process Management; Green Business Process Reengineering; Green Business Process Patterns; Process Patterns; Application Architecture Patterns; Cloud Computing Patterns},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The environmental impact of doing business becomes an increasingly relevant aspect for organizations, not only because of legal requirements but also because more customers care about. Most organizations, however, do not have comprehensive knowledge on how to restructure their business processes accordingly. In previous work we proposed green business process patterns that address the environmental impact explicitly as one possible solution. Beyond those patterns, we now provide a method to extract environmentally relevant patterns from existing patterns of different domains. Moreover, we present a set of such patterns related to automated business processes. The proposed approach as well as the identified patterns support stakeholders when analyzing their business processes with respect to the environmental impact and, therefore, supporting green business process reengineering.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-47&engl=1}
}
@inproceedings {INPROC-2013-46,
   author = {Oliver Kopp and Tobias Binz and Uwe Breitenb{\"u}cher and Frank Leymann},
   title = {{Winery - A Modeling Tool for TOSCA-based Cloud Applications}},
   booktitle = {Proceedings of 11th International Conference on Service-Oriented Computing (ICSOC'13)},
   publisher = {Springer Berlin Heidelberg},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {LNCS},
   volume = {8274},
   pages = {700--704},
   type = {Demonstration},
   month = {December},
   year = {2013},
   doi = {10.1007/978-3-642-45005-1_64},
   keywords = {Cloud Applications; Modeling; TOSCA; Management; Portability},
   language = {English},
   cr-category = {K.1 The Computer Industry,     K.6.4 System Management,     D.2.12 Software Engineering Interoperability},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {TOSCA is a new OASIS standard to describe composite applications and their management. The structure of an application is described by a topology, whereas management plans describe the application's management functionalities, e.g., provisioning or migration. Winery is a tool offering an HTML5-based environment for graph-based modeling of application topologies and defining reusable component and relationship types. Thereby, it uses TOSCA as internal storage, import, and export format. This demonstration shows how Winery supports modeling of TOSCA-based applications. We use the school management software Moodle as running example throughout the paper.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-46&engl=1}
}
@inproceedings {INPROC-2013-45,
   author = {Tobias Binz and Uwe Breitenb{\"u}cher and Florian Haupt and Oliver Kopp and Frank Leymann and Alexander Nowak and Sebastian Wagner},
   title = {{OpenTOSCA - A Runtime for TOSCA-based Cloud Applications}},
   booktitle = {Proceedings of 11th International Conference on Service-Oriented Computing (ICSOC'13)},
   publisher = {Springer Berlin Heidelberg},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {LNCS},
   volume = {8274},
   pages = {692--695},
   type = {Demonstration},
   month = {December},
   year = {2013},
   doi = {10.1007/978-3-642-45005-1_62},
   keywords = {TOSCA; Cloud Applications; Automation; Management; Portability},
   language = {English},
   cr-category = {K.1 The Computer Industry,     K.6.4 System Management,     D.2.12 Software Engineering Interoperability},
   contact = {a href=``http://www.iaas.uni-stuttgart.de/institut/mitarbeiter/binz''Tobias Binz/ a},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {TOSCA is a new standard facilitating platform independent description of Cloud applications. OpenTOSCA is a runtime for TOSCA-based Cloud applications. The runtime enables fully automated plan-based deployment and management of applications defined in the OASIS TOSCA packaging format CSAR. This paper outlines the core concepts of TOSCA and provides a system overview on OpenTOSCA by describing its modular and extensible architecture, as well as presenting our prototypical implementation. We demonstrate the use of OpenTOSCA by deploying and instantiating the school management and learning application Moodle.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-45&engl=1}
}
@inproceedings {INPROC-2013-44,
   author = {Tim Waizenegger and Matthias Wieland and Tobias Binz and Uwe Breitenb{\"u}cher and Frank Leymann},
   title = {{Towards a Policy-Framework for the Deployment and Management of Cloud Services}},
   booktitle = {SECURWARE 2013, The Seventh International Conference on Emerging Security Information, Systems and Technologies},
   editor = {Hans-Joachim Hof and Carla Westphall},
   address = {Barcelona, Spain},
   publisher = {IARIA},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {14--18},
   type = {Conference Paper},
   month = {August},
   year = {2013},
   isbn = {978-1-61208-298-1},
   keywords = {Cloud Computing; Security; Policy-Framework; TOSCA; Cloud Service; Cloud Management},
   language = {English},
   cr-category = {D.2.7 Software Engineering Distribution, Maintenance, and Enhancement,     D.2.9 Software Engineering Management,     D.2.13 Software Engineering Reusable Software},
   contact = {tim.waizenegger@informatik.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {As the adoption of Cloud Computing is growing, the automated deployment of cloud-based systems is becoming more and more important. New standards, such as TOSCA (OASIS), allow the modeling of interoperable Cloud services. It is now possible to build reusable and portable cloud services that can be (semi-) automatically deployed by different cloud-deployment-engines at various Cloud environments. However, there is still an acceptance problem among potential users, especially in the enterprise segment, that stems from security issues like data security. To improve security in automatic Cloud management engines, this paper proposes a framework for processing non-functional requirements of Cloud services.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-44&engl=1}
}
@inproceedings {INPROC-2013-43,
   author = {Tim Waizenegger and Matthias Wieland and Tobias Binz and Uwe Breitenb{\"u}cher and Florian Haupt and Oliver Kopp and Frank Leymann and Bernhard Mitschang and Alexander Nowak and Sebastian Wagner},
   title = {{Policy4TOSCA: A Policy-Aware Cloud Service Provisioning Approach to Enable Secure Cloud Computing}},
   booktitle = {On the Move to Meaningful Internet Systems: OTM 2013 Conferences},
   editor = {Robert Meersman and Herve Panetto and Tharam Dillon and Johann Eder and Zohra Bellahsene and Norbert Ritter and Pieter De Leenheer and Dou Deijing},
   address = {Heidelberg},
   publisher = {Springer Berlin Heidelberg},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science (LNCS)},
   volume = {8185},
   pages = {360--376},
   type = {Conference Paper},
   month = {September},
   year = {2013},
   isbn = {978-3-642-41029-1},
   doi = {10.1007/978-3-642-41030-7_26},
   keywords = {Cloud Computing, TOSCA, Cloud Service, Cloud Management, Policy-Framework, Security, Green-IT, Sustainable Cloud Service},
   language = {English},
   cr-category = {D.2.7 Software Engineering Distribution, Maintenance, and Enhancement,     D.2.9 Software Engineering Management,     D.2.13 Software Engineering Reusable Software},
   contact = {tim.waizenegger@informatik.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {With the growing adoption of Cloud Computing, automated deployment and provisioning systems for Cloud applications are becoming more prevalent. They help to reduce the onboarding costs for new customers as well as the financial impact of managing Cloud Services by automating these previously manual tasks. With the widespread use of such systems, the adoption of a common standard for describing Cloud applications will provide a crucial advantage by enabling reusable and portable applications. TOSCA, a newly published standard by OASIS with broad industry participation provides this opportunity. Besides the technical requirements of running and managing applications in the cloud, non-functional requirements, like cost, security, and environmental issues, are of special importance when moving towards the automated provisioning and management of Cloud applications. In this paper we demonstrate how non-functional requirements are defined in TOSCA using policies. We propose a mechanism for automatic processing of these formal policy definitions in a TOSCA runtime environment that we have developed based on the proposed architecture of the TOSCA primer. In order to evaluate our approach, we present prototypical implementations of security policies for encrypting databases and for limiting the geographical location of the Cloud servers. We demonstrate how our runtime environment is ensuring these policies and show how they affect the deployment of the application.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-43&engl=1}
}
@inproceedings {INPROC-2013-42,
   author = {Dimka Karastoyanova and Vasilios Andrikopoulos},
   title = {{eScienceSWaT – Towards an eScience Software Engineering Methodology}},
   booktitle = {Proceedings of the 17th International Enterprise Distributed Object Computing Conference Workshops (EDOCW 2013)},
   publisher = {IEEE Computer Society Conference Publishing Services},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {229--238},
   type = {Workshop Paper},
   month = {September},
   year = {2013},
   keywords = {eScience; scientific experiments; service-oriented systems/applications; patterns; Cloud computing; decision support; automation},
   language = {English},
   cr-category = {H.4.2 Information Systems Applications Types of Systems,     J.2 Physical Sciences and Engineering},
   contact = {karastoyanova@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {eScience is the field trying to provide IT support to scientists throughout the life cycle of scientific experiments. The major focus is on shortening the time to new discoveries and revealing knowledge about natural phenomena by providing software systems for different scientific tasks and for many domains. In this field, however, one can observe that there are no standardized and systematic approaches for developing the systems dealing with the processing and analysis of the large amounts of scientific data. In this paper we introduce eScienceSWaT, a software engineering methodology that aims at providing a systematic and user-friendly approach for building software applications for scientific experiments. The proposed approach considers the existing knowledge from computer science and software engineering but does not require scientists to be specialists in these fields. Furthermore, we present an architecture of a composable system enabling eScienceSWaT. The system is meant to guide scientists in developing their experiments and features decision support capabilities based on patterns. Both the methodology and the architecture apply approaches from Enterprise Computing, Cloud Computing and Software Engineering. In order to demonstrate the suitability of eScienceSWaT, we apply it to a scenario from the field of scientific simulations.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-42&engl=1}
}
@inproceedings {INPROC-2013-41,
   author = {Steve Strauch and Vasilios Andrikopoulos and Santiago G{\'o}mez S{\'a}ez and Frank Leymann},
   title = {{Implementation and Evaluation of a Multi-tenant Open-Source ESB}},
   booktitle = {Proceedings of the 2nd European Conference on Service-Oriented and Cloud Computing (ESOCC'13)},
   editor = {Lau Kung-Kiu and Lamersdorf Winfried and Pimentel Ernesto},
   publisher = {Springer Berlin Heidelberg},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science (LNCS)},
   volume = {8135},
   pages = {79--93},
   type = {Conference Paper},
   month = {September},
   year = {2013},
   isbn = {978-3-642-40650-8},
   keywords = {Multi-tenancy; Enterprise Service Bus (ESB); ESB benchmarking; JBI specification; Platform as a Service},
   language = {English},
   cr-category = {C.2.4 Distributed Systems},
   contact = {a href=``http://www.iaas.uni-stuttgart.de/institut/mitarbeiter/strauch''Steve Strauch/ a},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Offering applications as a service in the Cloud builds on the notion of application multi-tenancy. Multi-tenancy, the sharing of application instances and their underlying resources between users from different organizational domains, allows service providers to maximize resource utilization and reduce servicing costs per user. Realizing application multi-tenancy however requires suitable enabling mechanisms offered by their supporting middleware. Furthermore, the middleware itself can be multi-tenant in a similar fashion. In this work we focus on enabling multi-tenancy for one of the most important components in service-oriented middleware, the Enterprise Service Bus (ESB). In particular, we discuss the prototype realization of a multi-tenant aware ESB, using an open source solution as the basis. We then evaluate the performance of our proposed solution by an ESB-specific benchmark that we extended for multi-tenancy purposes.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-41&engl=1}
}
@inproceedings {INPROC-2013-39,
   author = {Christoph Demont and Uwe Breitenb{\"u}cher and Oliver Kopp and Frank Leymann and Johannes Wettinger},
   title = {{Towards Integrating TOSCA and ITIL}},
   booktitle = {Proceedings of the 5th Central-European Workshop on Services and their Composition (ZEUS 2013)},
   editor = {Oliver Kopp and Niels Lohmann},
   publisher = {CEUR-WS.org},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {CEUR Workshop Proceedings},
   volume = {1029},
   pages = {28--31},
   type = {Workshop Paper},
   month = {September},
   year = {2013},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The integration of low level management functionalities provided by TOSCA and high level processes as defined by ITIL may provide significant improvement opportunities to the application provider as on both levels workflow technology can be employed. In this paper, we present Key Performance Indicator Analysis Plans as first idea how both approaches can be integrated.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-39&engl=1}
}
@inproceedings {INPROC-2013-37,
   author = {C. Timurhan Sungur and Patrik Spiess and Nina Oertel and Oliver Kopp},
   title = {{Extending BPMN for Wireless Sensor Networks}},
   booktitle = {2013 IEEE International Conference on Business Informatics},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {109--116},
   type = {Conference Paper},
   month = {July},
   year = {2013},
   doi = {10.1109/CBI.2013.24},
   keywords = {WSN; BPMN; Extension; makeSense; MDD},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://www.project-makesense.eu/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Wireless sensor/actuator networks (WSNs) are hard to program, in particular so for business domain experts that have a good understanding of how WSNs can best be used to improve business operations. This contributes to hampering WSN adoption by enterprises. As business process modeling languages such as the Business Process Model and Notation (BPMN) are well accessible to domain experts, they can be used as a tool to facilitate WSN programming. In this paper, we explore the properties of WSNs that set them apart from traditional IT systems and use these properties to derive requirements for BPMN extensions that are tailored to the specifics of WSNs. We furthermore propose a set of BPMN extensions that fulfill these requirements and demonstrate that they are better suited for modeling WSN processes than standard BPMN.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-37&engl=1}
}
@inproceedings {INPROC-2013-36,
   author = {Vasilios Andrikopoulos and Zhe Song and Frank Leymann},
   title = {{Supporting the Migration of Applications to the Cloud through a Decision Support System}},
   booktitle = {Proceedings of the 6th IEEE International Conference on Cloud Computing (CLOUD 2013), June 27-July 2, 2013, Santa Clara Marriott, CA, USA},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {565--572},
   type = {Conference Paper},
   month = {July},
   year = {2013},
   doi = {10.1109/CLOUD.2013.128},
   keywords = {Cloud migration; decision support; provider selection; cost calculation; usage patterns},
   language = {English},
   cr-category = {D.2.0 Software Engineering General,     D.2.11 Software Engineering Software Architectures,     D.2.12 Software Engineering Interoperability},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2013-36/INPROC-2013-36.pdf},
   contact = {vasilios.andrikopoulos@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The motivation for this work is the necessity to be able to select an appropriate Cloud service provider offering for the migration of existing applications, based on cost minimization. While service providers offer pricing information publicly, and online tools allow for the calculation of cost for various Cloud offerings, the selection of which offering fits better the application requirements is left to application developers. For this purpose, this work proposes a migration decision support system that incorporates both offering matching and cost calculation, combining features from various approaches in the State of the Art. The proposed approach is then evaluated against existing tools.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-36&engl=1}
}
@inproceedings {INPROC-2013-30,
   author = {Alexander Nowak and Tobias Binz and Frank Leymann and Nicolas Urbach},
   title = {{Determining Power Consumption of Business Processes and their Activities to Enable Green Business Process Reengineering}},
   booktitle = {Proceedings of the 17th IEEE International EDOC Conference (EDOC 2013)},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {September},
   year = {2013},
   keywords = {Business Processes; Green Business Process Reengineering; Green Business Process Management; Power Consumption; Enterprise Topology; Environmental Impact; Web Service; Key Ecological Indicators},
   language = {English},
   cr-category = {H.4.1 Office Automation,     H.4.2 Information Systems Applications Types of Systems},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Knowing and optimizing the environmental impact of business processes is gaining momentum for today’s organizations. However, there is a lack of solutions that guide and support organizations in determining the power consumption of automated business processes, considering the resources and services used by that process. In this work we propose a comprehensive, multi-phased methodology and corresponding solutions that guide stakeholders through the methodology. As a proof-ofconcept we build up an experimental testbed capturing the power consumption of Web services and propagating this information to business processes. The proposed approach supports stakeholders analyzing their automated business processes with respect to their environmental impact and is therefore supporting green business process reengineering.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-30&engl=1}
}
@inproceedings {INPROC-2013-25,
   author = {Fei Li and Schahram Dustdar and Jakob Bardram and Martin Serrano and Manfred Hauswirth and Vasilios Andrikopoulos and Frank Leymann},
   title = {{EUPaaS - Elastic Ubiquitous Platform as a Service for Large-scale Ubiquitous Applications}},
   booktitle = {Proceedings of the 3rd International Conference on Cloud Computing and Service Science, CLOSER 2013, 8-10 May 2013, Aachen, Germany},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {309--314},
   type = {Conference Paper},
   month = {May},
   year = {2013},
   keywords = {Platform as a Service; Cloud Computing; Ubiquitous Computing; Healthcare; Hospital},
   language = {English},
   cr-category = {J.3 Life and Medical Sciences,     H.4.2 Information Systems Applications Types of Systems},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2013-25/INPROC-2013-25.pdf},
   contact = {li@dsg.tuwien.ac.at},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Large-scale ubiquitous computing applications are rapidly emerging in the fields of pervasive healthcare, smart cities and so on. They present unprecedented challenges to state-of-the-art ubiquitous systems in the respects of accommodating fluctuating user demands, handling volatile data quality and adaptation to complex system and user contexts. Driven by a motivating scenario in future mega-hospital environment, we propose to exploit the potential of cloud computing in supporting large-scale ubiquitous computing applications. This position paper will present the novel concept of EUPaaS (Elastic Ubiquitous Platform as a Service), outline the key research topics, and propose a cloud-based ubiquitous application platform.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-25&engl=1}
}
@inproceedings {INPROC-2013-21,
   author = {Johannes Wettinger and Vasilios Andrikopoulos and Steve Strauch and Frank Leymann},
   title = {{Enabling Dynamic Deployment of Cloud Applications Using a Modular and Extensible PaaS Environment}},
   booktitle = {Proceedings of the 6th International Conference on Cloud Computing (CLOUD 2013)},
   editor = {IEEE Computer Society},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {478--485},
   type = {Conference Paper},
   month = {July},
   year = {2013},
   keywords = {Middleware Abstraction; Infrastructure Abstraction; Middleware-oriented Deployment; PaaS Model; Cloud Computing},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures,     K.6 Management of Computing and Information Systems},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The Platform as a Service (PaaS) model promotes the development and deployment of applications on top of middleware solutions offered by the provider. Deploying an application in this model entails both the deployment of the application on top of the platform, but potentially also the deployment of the middleware components required by the application. Existing works enable the abstraction from the underlying infrastructure and allow for the creation of generic deployment plans for middleware components that automate the deployment of applications. In this paper we propose a middleware-oriented deployment approach that defines how the deployment of middleware components can be defined in a manner that allows to offer them as PaaS building blocks, and enable the automatic deployment of application components on them. We also present an evaluation of our proposal, together with the lessons learned during this activity.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-21&engl=1}
}
@inproceedings {INPROC-2013-20,
   author = {Uwe Breitenb{\"u}cher and Tobias Binz and Oliver Kopp and Frank Leymann},
   title = {{Pattern-based Runtime Management of Composite Cloud Applications}},
   booktitle = {Proceedings of the 3rd International Conference on Cloud Computing and Service Science, CLOSER 2013},
   publisher = {SciTePress Digital Library},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {May},
   year = {2013},
   keywords = {Application Management; Composite Cloud Services; Deployment; Patterns; Planlets},
   language = {English},
   cr-category = {K.6 Management of Computing and Information Systems},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The management of composite Cloud applications is a challenging problem as current available technologies provide management solutions that are tightly coupled to individual applications. Reusing and transferring management knowledge from one application to another in an automated way is a major issue. In this paper, we present a pattern-based approach which enables the decoupling of high level and low level management knowledge and show how both can be applied together fully automated to various kinds of applications.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-20&engl=1}
}
@inproceedings {INPROC-2013-19,
   author = {Jorge Cardoso and Tobias Binz and Uwe Breitenb{\"u}cher and Oliver Kopp and Frank Leymann},
   title = {{Cloud Computing Automation: Integrating USDL and TOSCA}},
   booktitle = {CAiSE 2013},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {LNCS},
   volume = {7908},
   pages = {1--16},
   type = {Conference Paper},
   month = {June},
   year = {2013},
   doi = {10.1007/978-3-642-38709-8_1},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Standardization efforts to simplify the management of cloud applications are being conducted in isolation. The objective of this paper is to investigate to which extend two promising specifications, USDL and TOSCA, can be integrated to automate the lifecycle of cloud applications. In our approach, we selected a commercial SaaS CRM platform, modeled it using the service description language USDL, modeled its cloud deployment using TOSCA, and constructed a prototypical platform to integrate service selection with deployment. Our evaluation indicates that a high level of integration is possible. We were able to fully automatize the remote deployment of a cloud service after it was selected by a customer in a marketplace. Architectural decisions emerged during the construction of the platform and were related to global service identification and access, multi-layer routing, and dynamic binding.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-19&engl=1}
}
@inproceedings {INPROC-2013-18,
   author = {Vasilios Andrikopoulos and Steve Strauch and Frank Leymann},
   title = {{Decision Support for Application Migration to the Cloud: Challenges and Vision}},
   booktitle = {Proceedings of the 3rd International Conference on Cloud Computing and Service Science (CLOSER'13)},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--7},
   type = {Conference Paper},
   month = {May},
   year = {2013},
   keywords = {Application migration; decision support; Cloud-enabling applications},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     D.2.11 Software Engineering Software Architectures},
   contact = {a href=``http://www.iaas.uni-stuttgart.de/institut/mitarbeiter/andrikopoulos''Vasilios Andrikopoulos/ a},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The success of Cloud computing has encouraged many application developers to consider migrating their applications to the Cloud. Given the early market dominance of the IaaS service model, many existing works focus on selecting the best service provider for a set of criteria related to the virtualization and hosting of the application. In this work, we aim to progress the State of the Art by formulating a vision of a decision support system that incorporates multiple dimensions and different analysis tasks in feedback relationships with each other. The research challenges that need to be addressed towards this direction are identified and related to the different aspects of migration of applications to the various Cloud service models.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-18&engl=1}
}
@inproceedings {INPROC-2013-17,
   author = {Steve Strauch and Vasilios Andrikopoulos and Uwe Breitenb{\"u}cher and Santiago G{\'o}mez S{\'a}ez and Oliver Kopp and Frank Leymann},
   title = {{Using Patterns to Move the Application Data Layer to the Cloud}},
   booktitle = {Proceedings of the 5th International Conference on Pervasive Patterns and Applications (PATTERNS'13)},
   publisher = {Xpert Publishing Services},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {26--33},
   type = {Conference Paper},
   month = {May},
   year = {2013},
   keywords = {Data layer; Cloud applications; Data migration; Cloud Data Patterns; Cloud data stores},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     D.2.11 Software Engineering Software Architectures,     H.3.4 Information Storage and Retrieval Systems and Software},
   contact = {a href=``http://www.iaas.uni-stuttgart.de/institut/mitarbeiter/strauch''Steve Strauch/ a},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Cloud services allow for hosting applications partially or completely in the Cloud by migrating their components and data. Especially with respect to data migration, a series of functional and non-functional challenges like data confidentiality arise when considering private and public Cloud data stores. In this paper we identify some of these challenges and propose a set of reusable solutions for them, organized together as a set of Cloud Data Patterns. Furthermore, we show how these patterns may impact the application architecture and demonstrate how they can be used in practice by means of a use case.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-17&engl=1}
}
@inproceedings {INPROC-2013-16,
   author = {Steve Strauch and Vasilios Andrikopoulos and Thomas Bachmann and Frank Leymann},
   title = {{Migrating Application Data to the Cloud Using Cloud Data Patterns}},
   booktitle = {Proceedings of the 3rd International Conference on Cloud Computing and Service Science (CLOSER'13)},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {36--46},
   type = {Conference Paper},
   month = {May},
   year = {2013},
   keywords = {application data migration; Cloud Data Patterns; Cloud Migration Scenarios; application refactoring},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     D.2.11 Software Engineering Software Architectures,     H.3.4 Information Storage and Retrieval Systems and Software},
   contact = {a href=``http://www.iaas.uni-stuttgart.de/institut/mitarbeiter/strauch''Steve Strauch/ a},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Taking advantage of the capabilities offered by Cloud computing requires either an application to be built specifically for it, or for existing applications to be migrated to it. In this work we focus on the latter case, and in particular on migrating the application data. Migrating data to the Cloud creates a series of technical, architectural and legal challenges that the State of the Art attempts to address. We organize such efforts into a set of migration scenarios and connect them with a list of reusable solutions for the application data migration in the form of patterns. From there we define an application data migration methodology and we demonstrate how it can be used in practice.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-16&engl=1}
}
@inproceedings {INPROC-2013-10,
   author = {Johannes Wettinger and Michael Behrendt and Tobias Binz and Uwe Breitenb{\"u}cher and Gerd Breiter and Frank Leymann and Simon Moser and Isabell Schwertle and Thomas Spatzier},
   title = {{Integrating Configuration Management with Model-Driven Cloud Management Based on TOSCA}},
   booktitle = {Proceedings of the 3rd International Conference on Cloud Computing and Services Science (CLOSER 2013); Aachen, Germany, May 8-10, 2013},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {437--446},
   type = {Conference Paper},
   month = {May},
   year = {2013},
   keywords = {Model-Driven Management; Configuration Management; Service Management; Cloud Services; DevOps},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures,     K.6 Management of Computing and Information Systems},
   contact = {E-Mail: johannes.wettinger@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The paradigm of Cloud computing introduces new approaches to manage IT services going beyond concepts originating in traditional IT service management. The main goal is to automate the whole management of services to reduce costs and to make management tasks less error-prone. Two different service management paradigms are used in practice: configuration management and model-driven Cloud management. The latter one aims to be a holistic management approach for services in the Cloud. However, both management paradigms are originating in different backgrounds, thus model-driven Cloud management does not cover all aspects of configuration management that are key for Cloud services. This paper presents approaches for integrating configuration management with model-driven Cloud management and how they can be realized based on the OASIS Topology and Orchestration Specification for Cloud Applications and Chef, a popular configuration management tool. These approaches enable the creation of holistic and highly portable service models.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-10&engl=1}
}
@inproceedings {INPROC-2013-09,
   author = {Johannes Wettinger and Oliver Kopp and Frank Leymann},
   title = {{Improving Portability of Cloud Service Topology Models Relying on Script-Based Deployment}},
   booktitle = {Proceedings of the 5th Central European Workshop on Services and their Composition (ZEUS 2013)},
   publisher = {CEUR Workshop Proceedings},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Workshop Paper},
   month = {February},
   year = {2013},
   issn = {1613-0073},
   keywords = {Portability; Service Topology; Topology Model; Service Deployment; Cloud Computing},
   language = {English},
   cr-category = {D.2.13 Software Engineering Reusable Software,     D.2.11 Software Engineering Software Architectures},
   contact = {E-Mail: johannes.wettinger@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Portability is key for services running in the Cloud to prevent vendor lock-in. Today, many Cloud services are portable and can thus be moved from one Cloud provider to another. However, the management of these services is often bound to provider-specific management tooling. Thus, the way of management of a particular Cloud service may completely change when moving it to another Cloud provider. This paper presents concepts to improve the portability of Cloud service topology models that are deployed and managed using scripts. We highlight the challenges of a semi-automatic procedure to generate portable TOSCA-compliant topology model components based on Juju topology model components.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-09&engl=1}
}
@inproceedings {INPROC-2013-08,
   author = {Sebastian Wagner and Oliver Kopp and Frank Leymann},
   title = {{Consolidation of Interacting BPEL Process Models with Fault Handlers}},
   booktitle = {Proceedings of the 5th Central-European Workshop on Services and their Composition (ZEUS 2013)},
   address = {Rostock},
   publisher = {CEUR Workshop Proceedings},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Workshop Paper},
   month = {February},
   year = {2013},
   keywords = {BPEL; Choreography; Process Consolidation},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://zeus-workshop.eu/2013/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The interaction behavior between processes of organizations and their suppliers can be modeled by using choreographies. When an organization decides to gain more control about their suppliers and to minimize transaction costs they may decide to insource these companies. This also requires the integration of the partner processes into the organization. In previous work we proposed an approach to merge (consolidate) interacting BPEL process models of different partners into a single process model by deriving control flow links between the process models from their interaction specification. In this work we are detailing this consolidation approach. Thereby, special attention is turned on extending the consolidation operations in a way that process models with fault handlers can be merged.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-08&engl=1}
}
@inproceedings {INPROC-2013-07,
   author = {Tobias Binz and Uwe Breitenb{\"u}cher and Oliver Kopp and Frank Leymann and Andreas Wei{\ss}},
   title = {{Improve Resource-Sharing through Functionality-Preserving Merge of Cloud Application Topologies}},
   booktitle = {Proceedings of the 3rd International Conference on Cloud Computing and Service Science, CLOSER 2013, 8-10 May 2013, Aachen, Germany},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {May},
   year = {2013},
   keywords = {Application Topology; Merge; Resource Sharing; Multi-tenancy; Cloud Computing; TOSCA},
   language = {English},
   cr-category = {K.6 Management of Computing and Information Systems},
   contact = {a href=``http://www.iaas.uni-stuttgart.de/institut/mitarbeiter/binz''Tobias Binz/ a},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Resource sharing is an important aspect how cost savings in cloud computing are realized. This is especially important in multi-tenancy settings, where different tenants share the same resource. This paper presents an approach to merge two application topologies into one, while on the one hand preserving the functionality of both applications and on the other hand enabling sharing of similar components. Previous work has not addressed this due to the lack of ways to describe topologies of composite applications in a decomposed, formal, and machine-readable way. New standardization initiatives, such as TOSCA, provide a way to describe application topologies, which are also portable and manageable. We propose an approach, realization, and architecture enabling a functionality-preserving merge of application topologies. To validate our approach we prototypically implemented and applied it to merge a set of test cases. All in all, the functional-preserving merge is a method to support the optimization and migration of existing applications to the cloud, because it increases resource sharing in the processed application topologies.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-07&engl=1}
}
@inproceedings {INPROC-2013-03,
   author = {Sebastian Wagner and Dieter Roller and Oliver Kopp and Tobias Unger and Frank Leymann},
   title = {{Performance Optimizations for Interacting Business Processes}},
   booktitle = {Proceedings of the first IEEE International Conference on Cloud Engineering (IC2E 2013)},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--7},
   type = {Conference Paper},
   month = {March},
   year = {2013},
   doi = {10.1109/IC2E.2013.34},
   keywords = {Workflow Engine; BPEL; Choreography; Performance Optimization; Process Merge; Green Computing},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Choreographies describe the interaction behavior of processes at design time: a choreography defines when messages have to be exchanged between the involved processes during their runtime. In the context of Web services and the de-facto workflow language BPEL, SOAP is used to encode the messages. When complex messages are exchanged between the processes, this can become costly and time consuming with respect to the overall execution time of a choreography. In this work, we suggest three different performance optimization techniques for workflow engines to reduce the number of message exchanges between the interacting processes and hence, to decrease the execution times and costs of the choreographies: intra-engine transport, service request caching, and inline execution. We describe how these techniques are implemented in a workflow engine. Performance measurements are carried out to determine the performance improvements that are achieved with each optimization technique. We further show that the optimizations also affect the energy consumption of the workflow engine.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2013-03&engl=1}
}
@inproceedings {INPROC-2012-48,
   author = {Paul J. Kearney and David A. Sinclair and Sebastian Wagner},
   title = {{Security Design Patterns in the MASTER Workbench}},
   booktitle = {Proceedings of the First International Workshop on Cyberpatterns: Unifying Design Patterns with Security, Attack and Forensic Patterns},
   address = {Abingdon, UK},
   publisher = {Oxford Brookes University},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {65--69},
   type = {Workshop Paper},
   month = {July},
   year = {2012},
   keywords = {business process; design pattern; model-driven design; security},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://cms.brookes.ac.uk/staff/HongZhu/CyberPatterns2012/index.html},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {This paper describes pattern-related aspects of the prototype Protection and Assessment Workbench developed as part of the MASTER EU 7th Framework collaborative research project. The Workbench supports a model-driven design process within the overall MASTER methodology. It includes a Protection and Regulatory Model (PRM) tool that is a step towards turning the Workbench into an ‘organisational memory’ for design practices that accumulates and improves over time. PRMs are essentially control process design patterns that incorporate proven strategies in a re-usable form, saving time and improving quality and consistency.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-48&engl=1}
}
@inproceedings {INPROC-2012-47,
   author = {Steve Strauch and Vasilios Andrikopoulos and Uwe Breitenb{\"u}cher and Oliver Kopp and Leymann Frank},
   title = {{Non-Functional Data Layer Patterns for Cloud Applications}},
   booktitle = {Proceedings of the 4th IEEE International Conference on Cloud Computing Technology and Science (CloudCom'12)},
   publisher = {IEEE Computer Society Press},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {601--605},
   type = {Conference Paper},
   month = {December},
   year = {2012},
   keywords = {data layer; cloud applications; data migration; cloud data patterns; cloud data stores},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     D.2.11 Software Engineering Software Architectures,     H.3.4 Information Storage and Retrieval Systems and Software},
   contact = {a href=``http://www.iaas.uni-stuttgart.de/institut/mitarbeiter/strauch''Steve Strauch/ a},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Cloud services allow for hosting applications partially or completely in the Cloud by migrating their components and data. Especially with respect to data migration, a series of functional and non-functional challenges like data confidentiality arise when considering private and public Cloud data stores. In this paper we identify some of these challenges and propose a set of reusable solutions focusing on the non-functional aspects, organized together as a set of Cloud Data Patterns.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-47&engl=1}
}
@inproceedings {INPROC-2012-46,
   author = {Steve Strauch and Vasilios Andrikopoulos and Frank Leymann and Dominik Muhler},
   title = {{ESB^MT: Enabling Multi-Tenancy in Enterprise Service Buses}},
   booktitle = {Proceedings of the 4th IEEE International Conference on Cloud Computing Technology and Science (CloudCom'12)},
   publisher = {IEEE Computer Society Press},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {456--463},
   type = {Conference Paper},
   month = {December},
   year = {2012},
   keywords = {multi-tenancy; enterprise service bus; cloud-enabled middleware},
   language = {English},
   cr-category = {C.2.4 Distributed Systems},
   contact = {a href=``http://www.iaas.uni-stuttgart.de/institut/mitarbeiter/strauch''Steve Strauch/ a},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Multi-tenancy is an essential property of Cloud computing. It helps service providers to maximize resource utilization and reduce servicing costs per customer. It is therefore important for key components of the contemporary enterprise environment like the Enterprise Service Bus (ESB) to support and enable multi-tenancy. For this purpose, in this work we investigate the requirements for multi-tenant ESB solutions, propose an implementation-agnostic ESB architecture that addresses these requirements, and discuss our proof-of-concept realization of this architecture.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-46&engl=1}
}
@inproceedings {INPROC-2012-45,
   author = {Steve Strauch and Vasilios Andrikopoulos and Santiago G{\'o}mez S{\'a}ez and Frank Leymann and Dominik Muhler},
   title = {{Enabling Tenant-Aware Administration and Management for JBI Environments}},
   booktitle = {Proceedings of the 5th International Conference on Service-Oriented Computing and Applications (SOCA'12)},
   publisher = {IEEE Computer Society Conference Publishing Services},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {206--213},
   type = {Conference Paper},
   month = {December},
   year = {2012},
   isbn = {978-1-4673-4775-4},
   keywords = {Multi-tenancy; Enterprise Service Bus (ESB); JBI specification; Platform as a Service},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     C.4 Performance of Systems,     D.2.11 Software Engineering Software Architectures},
   contact = {a href=``http://www.iaas.uni-stuttgart.de/institut/mitarbeiter/strauch''Steve Strauch/ a},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Enterprise Service Buses (ESBs) constitute a core middleware technology for each modern Service-Oriented Architecture (SOA) solution. Given the popularity of the Cloud paradigm, which is based on fundamental SOA concepts, it is only therefore natural to look into how ESBs can be transformed into native building blocks for Cloud platforms. As a first step of this effort, in this work we investigate how ESBs can become multi-tenant aware, i.e. able to support multiple tenants and their users sharing the same ESB instance. A generalized architecture based on the JBI specification implemented by a number of open source ESBs is presented for this purpose. We demonstrate the feasibility of our proposal by means of a proof of concept realization and we evaluate the performance of our solution against a non multi-tenant ESB that was used as the baseline for our implementation.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-45&engl=1}
}
@inproceedings {INPROC-2012-44,
   author = {Sebastian Wagner and Christoph Fehling and Dimka Karastoyanova and David Schumm},
   title = {{State Propagation-based Monitoring of Business Transactions}},
   booktitle = {Proceedings of the 2012 IEEE International Conference on Service-Oriented Computing and Applications},
   publisher = {IEEE Xplore},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {December},
   year = {2012},
   doi = {10.1109/SOCA.2012.6449464},
   keywords = {Business Transactions, Process View, BPEL, Process Merge, Process Split, Monitoring, State Propagation},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Business analysts want to monitor the status of their business goals in a business-centric manner, without any knowledge of the actual implementation artifacts that contribute achieving these goals. Business transactions are one means to represent business goals and requirements. A business transaction is typically implemented by a choreography of different parties contributing to the accomplishment of the common agreement. To meet the constantly changing requirements for all parties in a business transaction choreographies often have to be adapted (e.g. change in the distribution on different execution environments). The resulting challenge is that the execution state of a choreography executed on several locations has to be propagated to the business analyst to enable monitoring of (adapted) business transactions. For this purpose we introduce a meta-model and state model of business transactions. Based on these models, we introduce a two-stage monitoring approach involving state propagation of the execution status of the adapted choreography to the original choreography and from there to the business transaction.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-44&engl=1}
}
@inproceedings {INPROC-2012-43,
   author = {Alexander Nowak and Dimka Karastoyanova and Frank Leymann and Andrej Rapoport and David Schumm},
   title = {{Flexible Information Design for Business Process Visualizations}},
   booktitle = {Proceedings of the 2012 IEEE International Conference on Service-Oriented Computing and Applications},
   publisher = {IEEE Xplore},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {December},
   year = {2012},
   doi = {10.1109/SOCA.2012.6449436},
   keywords = {Business Process Management, Process Visualization, Process Analysis, Service-oriented Architecture},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   contact = {Senden Sie eine E-Mail an alexander.nowak@iaas.uni-stuttgart.de.},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Profound understanding of business processes is a key success factor for Business Process Management (BPM). As more and more analytical information like runtime data from process execution or statistical data from business intelligence are available the problem of business process complexity becomes apparent. To improve time-to-productivity as well as to save costs process-relevant information needs to be provided as fast as possible while considering easy and fast interpretation and dynamic changes in stakeholders’ demands. The static and use-case specific creation or modification of process visualizations shown in current approaches and tools, however, is complex, time consuming, inflexible and thus costly. To address these shortcomings, we introduce a template-based approach that decouples the creation of visualization templates from concrete process visualizations. The binding of customization points of visualization templates to analytical process information is supported by a graphical editor that enables customization of visualizations in a fast and flexible manner. Moreover, due to the separation of concerns, our approach improves the usability of process visualizations because templates may be created by graphic experts independently from specific visualization demands. The feasibility of our concept is demonstrated by a prototypical implementation.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-43&engl=1}
}
@inproceedings {INPROC-2012-42,
   author = {Michael Reiter and Uwe Breitenb{\"u}cher and Oliver Kopp and Dimka Karastoyanova},
   title = {{Quality of Data Driven Simulation Workflows}},
   booktitle = {2012 8th IEEE International Conference on eScience},
   editor = {IEEE},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {October},
   year = {2012},
   doi = {10.1109/eScience.2012.6404417},
   keywords = {controlling by quality of data; simulation workflows; workflow management system; e-science},
   language = {English},
   cr-category = {H.4.1 Office Automation,     I.6.7 Simulation Support Systems},
   contact = {michael.reiter@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Simulations are characterized by long running calculations and complex data handling tasks accompanied by non-trivial data dependencies. The workflow technology helps to automate and steer such simulations. Quality of Data frameworks are used to determine the goodness of simulation data, e.g., they analyze the accuracy of input data with regards to the usability within numerical solvers. In this paper, we present generic approaches using evaluated Quality of Data to steer simulation workflows. This allows for ensuring that the predefined requirements such as a precise final result or a short execution time will be met even after the execution of simulation workflow has been started. We discuss mechanisms for steering a simulation on all relevant levels – workflow, service, algorithms, and define a unifying approach to control such workflows. To realize Quality of Data-driven workflows, we present an architecture realizing the presented approach and a WS-Policy-based language to describe Quality of Data requirements and capabilities.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-42&engl=1}
}
@inproceedings {INPROC-2012-39,
   author = {Dimka Karastoyanova and Dimitrios Dentsas and David Schumm and Mirko Sonntag and Lina Sun and Karolina Vukojevic-Haupt},
   title = {{Service-based Integration of Human Users in Workflow-driven Scientific Experiments}},
   booktitle = {Proceedings of the 8th IEEE International Conference on eScience (eScience 2012)},
   publisher = {IEEE Computer Society Press},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--8},
   type = {Conference Paper},
   month = {October},
   year = {2012},
   doi = {10.1109/eScience.2012.6404435},
   keywords = {Scientific Workflows; Human Task Management; Cyber-infrastructure; Communication Services},
   language = {English},
   cr-category = {H.4.1 Office Automation,     I.6.7 Simulation Support Systems},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Through increased usage of information technology in research and practice ever more tasks can be automated to make scientific experiments more efficient in terms of cost, speed, accuracy, and flexibility. Scientific workflows have proven useful for the automation of scientific computations. However, not all tasks of an experiment can be automated. Some decisions still need to be made by human users, for instance, decisions how an automated system should proceed in an exceptional situation. To address the need for integration of human users in such automated systems, we propose the concept of Human Communication Flows, which specify the way how an application, such as a scientific workflow, can interact with a human user. We developed a human communication framework that implements these Communication Flows in a pipes-and-filters architecture supporting notifications and request-response interactions. For usage within a scientific workflow we created workflow fragments, which implement the interaction with the framework. Different Communication Services can be plugged into this framework to account for different communication capabilities of human users.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-39&engl=1}
}
@inproceedings {INPROC-2012-35,
   author = {Dimka Karastoyanova and Manuel Carro and Dragan Ivanovic and Claudia Di Napoli and Maurizio Giordano and Zsolt Nem{\'e}th and Cesare Pautasso},
   title = {{Research Challenges on Service Technology Foundations}},
   booktitle = {Proceedings of the Workshop on ``European Software Services and Systems Research - Results and Challenges'' (at ICSE 2012)},
   address = {Zurich, Switzerland},
   publisher = {IEEE Press, NJ, USA},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {27--33},
   type = {Workshop Paper},
   month = {May},
   year = {2012},
   isbn = {978-1-4673-1067-3},
   keywords = {service-based applications; challenges; technologies; formal models; service compositions; business transactions; KPIs; service networks; minitoring and adaptation; nature-inspired approches; chemical composition; liquid computing; Cloud computing},
   language = {English},
   cr-category = {H.1 Models and Principles,     H.4 Information Systems Applications,     D.2 Software Engineering},
   contact = {Dimka Karastoyanova},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {This work gives an overview of the future research challenges on enabling technologies for service-based applications that have been identified in the network of excellence S-Cube. Service-based applications comprise three layers: business processes, service compositions and services and service infrastructures. The goal of this work is to present a roadmap for future research in technologies for software and system services.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-35&engl=1}
}
@inproceedings {INPROC-2012-33,
   author = {Uwe Breitenb{\"u}cher and Tobias Binz and Oliver Kopp and Frank Leymann and David Schumm},
   title = {{Vino4TOSCA: A Visual Notation for Application Topologies based on TOSCA}},
   booktitle = {Proceedings of the 20th International Conference on Cooperative Information Systems (CoopIS 2012)},
   publisher = {Springer-Verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science},
   type = {Conference Paper},
   month = {September},
   year = {2012},
   doi = {10.1007/978-3-642-33606-5_25},
   keywords = {TOSCA; Modeling; Visual Notation; Application Topologies},
   language = {English},
   cr-category = {H.1.2 User/Machine Systems},
   contact = {uwe.breitenbuecher@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {A major difficulty in enterprise computing is the modeling of complex application topologies consisting of numerous individual components and their relationships. Especially in the context of cloud computing, the Topology and Orchestration Specification for Cloud Applications (TOSCA) has been proposed recently for standardization to tackle this issue. However, TOSCA currently lacks a well-defined visual notation enabling effective and efficient communication in order to transport the semantics of the encoded information to human beings. In this paper, we propose a visual notation for TOSCA based on established usability research which provides additional concepts for visual modularization and abstraction of large application topologies.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-33&engl=1}
}
@inproceedings {INPROC-2012-32,
   author = {Katharina G{\"o}rlach and Frank Leymann},
   title = {{Dynamic Service Provisioning for the Cloud}},
   booktitle = {Proceedings of the 9th International Conference on Services Computing (SCC) 2012},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {555--561},
   type = {Conference Paper},
   month = {June},
   year = {2012},
   doi = {10.1109/SCC.2012.30},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures},
   contact = {goerlach@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {This paper introduces a method realizing dynamic provisioning of services in a distributed environment. Depending on a particular state of infrastructure the call of a service can lead to a new instance in the infrastructure or to using an existing instance. Hence, the dynamic deployment allows optimized distribution of service instances within a certain infrastructure. The paper introduces a context model for services that are registered in a distributed runtime environment. Furthermore, algorithms are introduced determining the need for instantiation as well as the best location for deployment. Hence, the best location is determined by correlating the context model, the certain state of infrastructure as well as data transfer costs.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-32&engl=1}
}
@inproceedings {INPROC-2012-29,
   author = {Mirko Sonntag and Michael Hahn and Dimka Karastoyanova},
   title = {{Mayflower - Explorative Modeling of Scientific Workflows with BPEL}},
   booktitle = {Proceedings of the Demo Track of the 10th International Conference on Business Process Management (BPM 2012), CEUR Workshop Proceedings, 2012},
   publisher = {CEUR Workshop Proceedings},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--5},
   type = {Workshop Paper},
   month = {September},
   year = {2012},
   keywords = {Scientific workflows; Model-as-you-go; SOA; BPEL},
   language = {English},
   cr-category = {H.4.1 Office Automation,     I.6.5 Model Development,     D.2.2 Software Engineering Design Tools and Techniques},
   ee = {http://www.ceur-ws.org},
   contact = {sonntag@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Using workflows for scientific calculations, experiments and simulations has been a success story in many cases. Unfortunately, most of the existing scientific workflow systems implement proprietary, non-standardized workflow languages, not taking advantage of the achievements of the conventional business workflow technology. It is only natural to combine these two research branches in order to harness the strengths of both. In this demonstration, we present Mayflower, a workflow environment that enables scientists to model workflows on the fly using extended business workflow technology. It supports the typical trial-and-error approach scientists follow when developing their experiments, computations or simulations and provides scientist with all crucial characteristics of the workflow technology. Additionally, beneficial to the business stakeholders, Mayflower brings additional simplification in workflow de-velopment and debugging.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-29&engl=1}
}
@inproceedings {INPROC-2012-27,
   author = {Uwe Breitenb{\"u}cher and Oliver Kopp and Frank Leymann and Michael Reiter and Dieter Roller and Tobias Unger},
   title = {{Six Strategies for Building High Performance SOA Applications}},
   booktitle = {Proceedings of the 4th Central-European Workshop on Services and their Composition, ZEUS-2012},
   editor = {Andreas Sch{\"o}nberger and Oliver Kopp and Niels Lohmann},
   publisher = {CEUR-WS.org},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {CEUR Workshop Proceedings},
   volume = {847},
   pages = {120--127},
   type = {Workshop Paper},
   month = {May},
   year = {2012},
   keywords = {Service-oriented Architecture; High Performance; Strategies},
   language = {English},
   cr-category = {C.4 Performance of Systems},
   ee = {http://zeus-workshop.eu/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The service-oriented architecture (SOA) concepts such as loose coupling may have negative impact on the overall execution performance of a single request. There are ways to facilitate high performance applications which benefit from this kind of architectural style compensating the caused overhead significantly. This paper gives an overview on six high level strategies to improve the performance of SOAs with a central service bus and presents how to apply them to build high performance service-oriented applications without corrupting the SOA paradigm and concepts on the technical level.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-27&engl=1}
}
@inproceedings {INPROC-2012-23,
   author = {Oliver Kopp and Tobias Binz and Uwe Breitenb{\"u}cher and Frank Leymann},
   title = {{BPMN4TOSCA: A Domain-Specific Language to Model Management Plans for Composite Applications}},
   booktitle = {4th International Workshop on the Business Process Model and Notation},
   editor = {Jan Mendling and Matthias Weidlich},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Business Information Processing},
   volume = {125},
   pages = {38--52},
   type = {Workshop Paper},
   month = {September},
   year = {2012},
   doi = {10.1007/978-3-642-33155-8_4},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://emisa2012.univie.ac.at/index.php?t=bpmn},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {TOSCA is an upcoming standard to capture application topologies and their management in a portable way. Management aspects include provisioning, operation and deprovisioning of an application. Management plans capture these aspects in workflows. BPMN 2.0 as general-purpose language can be used to model these workflows. There is, however, no tailored support for management plans in BPMN. This paper analyzes TOSCA with the focus on requirements on workflow modeling languages to come up with a strong link to the application topology with the goal to improve modeling support. To simplify the modeling of management plans, we introduce BPMN4TOSCA, which extends BPMN with four TOSCA-specific elements: TOSCA Topology Management Task, TOSCA Node Management Task, TOSCA Script Task, and TOSCA Data Object. Portability is ensured by a transformation of BPMN4TOSCA to plain BPMN. A prototypical modeling tool supports the strong link between the management plan and the TOSCA topology.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-23&engl=1}
}
@inproceedings {INPROC-2012-22,
   author = {Christoph Fehling and Thilo Ewald and Frank Leymann and Michael Pauly and Jochen R{\"u}tschlin and David Schumm},
   title = {{Capturing Cloud Computing Knowledge and Experience in Patterns}},
   booktitle = {Proceedings of the 2012 IEEE International Conference on Cloud Computing (CLOUD 2012)},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--8},
   type = {Conference Paper},
   month = {June},
   year = {2012},
   doi = {10.1109/CLOUD.2012.124},
   language = {German},
   cr-category = {C.0 Computer Systems Organization, General,     C.2.4 Distributed Systems,     D.2.2 Software Engineering Design Tools and Techniques,     D.2.3 Software Engineering Coding Tools and Techniques,     D.2.7 Software Engineering Distribution, Maintenance, and Enhancement},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The industry-driven evolution of cloud computing tends to obfuscate the common underlying architectural concepts of cloud offerings and their implications on hosted applications. Patterns are one way to document such architectural principles and to make good solutions to reoccurring (architectural) cloud challenges reusable. To capture cloud computing best practice from existing cloud applications and provider-specific documentation, we propose to use an elaborated pattern format enabling abstraction of concepts and reusability of knowledge in various use cases. We present a detailed step-by-step pattern identification process supported by a pattern authoring toolkit. We continuously apply this process to identify a large set of cloud patterns. In this paper, we introduce two new cloud patterns we identified in industrial scenarios recently. The approach aims at cloud architects, developers, and researchers alike to also apply this pattern identification process to create traceable and well-structured pieces of knowledge in their individual field of expertise. As entry point, we recap challenges introduced by cloud computing in various domains.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-22&engl=1}
}
@inproceedings {INPROC-2012-21,
   author = {Tobias Binz and Frank Leymann and Alexander Nowak and David Schumm},
   title = {{Improving the Manageability of Enterprise Topologies Through Segmentation, Graph Transformation, and Analysis Strategies}},
   booktitle = {Proceedings of 2012 Enterprise Distributed Object Computing Conference (EDOC)},
   publisher = {IEEE Computer Society Conference Publishing Services},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {September},
   year = {2012},
   doi = {10.1109/EDOC.2012.17},
   keywords = {enterprise topology; enterprise topology graph; cloud; formalization; search; IT consolidation},
   language = {English},
   cr-category = {K.6 Management of Computing and Information Systems,     D.2.12 Software Engineering Interoperability},
   contact = {a href=``http://www.iaas.uni-stuttgart.de/institut/mitarbeiter/binz''Tobias Binz/ a},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Software systems running in an enterprise consist of countless components, having complex dependencies, are hosted on physical or virtualized environments, and are scattered across the infrastructure of an enterprise, ranging from on-premise data centers up to public cloud deployments. The resulting topology of the current IT landscape of an enterprise is often extremely complex. We show that information about this complex ecosystem can be captured in a graph-based structure, the enterprise topology graph. We argue that by using such a graph-based representation many challenges in Enterprise Architecture Management (EAM) can be tackled through the aid of graph processing algorithms. However, the high complexity of an enterprise topology graph is the main obstacle to this approach. An enterprise topology graph may consist of millions of nodes, each representing an element of the enterprise IT landscape. Further, these nodes comprise a large variety of properties and relationships, making the topology hardly manageable by human users and software tools. To address this complexity problem, we propose different mechanisms to make enterprise topology graphs manageable. Segmentation techniques, tailored to specific use cases, extract manageable segments from the enterprise topology graph. Based on a set of formally defined transformation operations we then demonstrate the power of the approach in three application scenarios.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-21&engl=1}
}
@inproceedings {INPROC-2012-19,
   author = {David Schumm and Johanna Barzen and Frank Leymann and Lutz Ellrich},
   title = {{A Pattern Language for Costumes in Films}},
   booktitle = {Proceedings of the 17th European Conference on Pattern Languages of Programs (EuroPLoP 2012)},
   editor = {Christian Kohls and Andreas Fiesser},
   address = {New York, NY, USA},
   publisher = {ACM},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--25},
   type = {Conference Paper},
   month = {July},
   year = {2012},
   isbn = {978-1-4503-2943-9},
   doi = {10.1145/2602928.2603083},
   keywords = {Costume Language; Vestimentary Communication; Empirical Film Analysis; Pattern Language},
   language = {English},
   cr-category = {H.3.1 Content Analysis and Indexing,     I.5.2 Pattern Recognition Design Methodology,     J.5 Arts and Humanities},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {A closer look behind the scenes of film making and media science reveals that the costumes used in film productions are products of a complex construction process. The costume designer has to put a lot of creative and investigative effort into the creation of costumes to provide the right clothes for a particular role, which means the costume reflects the place and time of play as well as it shows understanding of the characteristics of the role, actor and screenplay overall. Consequently, the creation of a costume is a difficult problem that is more or less occurring often, whereas the frequency of problem occurrence strongly depends on the genre and specifics of the film. For the genre of Western films, for example, the costume of a Wild West Sheriff is qualified for identification and description as a pattern because it appears frequently. In this paper, we propose a pattern language for composing costume patterns through a rich set of composition operators, more fine-grained costume patterns, and costume primitives. The pattern language aims at supporting media science, costume design, and costume management through providing a basis for the development of advanced information systems assisting the management of costumes considering their inherent structure and relations between their constituent parts. Our pattern approach is exemplified through deep-dive modeling of two costume patterns.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-19&engl=1}
}
@inproceedings {INPROC-2012-18,
   author = {Tobias Binz and Christoph Fehling and Frank Leymann and Alexander Nowak and David Schumm},
   title = {{Formalizing the Cloud through Enterprise Topology Graphs}},
   booktitle = {Proceedings of 2012 IEEE International Conference on Cloud Computing},
   publisher = {IEEE Computer Society Conference Publishing Services},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {742--749},
   type = {Conference Paper},
   month = {June},
   year = {2012},
   doi = {10.1109/CLOUD.2012.143},
   keywords = {enterprise topology; enterprise topology graph; EAM; topology abstraction; segmentation; aggregation},
   language = {English},
   cr-category = {K.6 Management of Computing and Information Systems,     D.2.12 Software Engineering Interoperability},
   contact = {a href=``http://www.iaas.uni-stuttgart.de/institut/mitarbeiter/binz''Tobias Binz/ a},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Enterprises often have no integrated and comprehensive view of their enterprise topology describing their entire IT infrastructure, software, on-premise and off-premise services, processes, and their interrelations. Especially due to acquisitions, mergers, reorganizations, and outsourcing there is no clear ‘big picture’ of the enterprise topology. Through this lack, management of applications becomes harder and duplication of components and information systems increases. Furthermore, the lack of insight makes changes in the enterprise topology like consolidation, migration, or outsourcing more complex and error prone which leads to high operational cost. In this paper we propose Enterprise Topology Graphs (ETG) as formal model to describe an enterprise topology. Based on established graph theory ETG bring formalization and provability to the cloud. They enable the application of proven graph algorithms to solve enterprise topology research problems in general and cloud research problems in particular. For example, we present a search algorithm which locates segments in large and possibly distributed enterprise topologies using structural queries. To illustrate the power of the ETG approach we show how it can be applied for IT consolidation to reduce operational costs, increase flexibility by simplifying changes in the enterprise topology, and improve the environmental impact of the enterprise IT.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-18&engl=1}
}
@inproceedings {INPROC-2012-16,
   author = {David Schumm and Dimitrios Dentsas and Michael Hahn and Dimka Karastoyanova and Frank Leymann and Mirko Sonntag},
   title = {{Web Service Composition Reuse through Shared Process Fragment Libraries}},
   booktitle = {Proceedings of the 12th International Conference on Web Engineering (ICWE 2012 Demos)},
   publisher = {Springer-Verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science},
   pages = {1--4},
   type = {Workshop Paper},
   month = {July},
   year = {2012},
   doi = {10.1007/978-3-642-31753-8_53},
   keywords = {Process Reuse; Service Composition; Web Services; BPEL; Process Fragments.},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     D.2.2 Software Engineering Design Tools and Techniques,     H.3.5 Online Information Services,     H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {More and more application functionality is provided for use over corporate and public networks. Standardized technology stacks, like Web services, provide abstraction from the internal implementation. Coarse-grained units of Web service composition logic can be made reusable by capturing it as ‘process fragment’. Such fragments can be shared over the Web to simplify and accelerate development of process-based service compositions. In this demonstration, we present a framework consisting of an Eclipse-based process design environment that is integrated with a Web-based process fragment library. The framework enables extracting process fragments, publishing and sharing them on the Web, as well as search, retrieval, and their reuse in a given process. Process fragments can be shared with others using a Web frontend or through a plug-in within the process design environment which is building on Web service technology.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-16&engl=1}
}
@inproceedings {INPROC-2012-12,
   author = {Frank Leymann},
   title = {{Linked Compute Units and Linked Experiments: Using Topology and Orchestration Technology for Flexible Support of Scientific Applications}},
   booktitle = {Software Service and Application Engineering - Essays Dedicated to Bernd Kr{\"a}mer on the Occasion of His 65th Birthday},
   editor = {Maritta Heisel},
   publisher = {Springer Berlin Heidelberg},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {LNCS},
   volume = {7365},
   pages = {71--80},
   type = {Workshop Paper},
   month = {May},
   year = {2012},
   isbn = {978-3-642-30834-5},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://www.springer.com/computer/theoretical+computer+science/book/978-3-642-30834-5},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Being able to run and manage applications in different environments (especially in clouds) is an urgent requirement in industry. Such portability requires a standard language to define both, the structure of an application as well as its management behavior. This paper sketches the main ingredients of such a language and explains its underlying concepts. Next, the concept of linked compute units is introduced providing verifiability of the results of dataintense work. Considering human beings in this concept results in linked social compute units. The benefits of describing scientific applications by this concept are worked out. The resulting vision of being able to run in silico experiments everywhere and its supporting high-level architecture is presented.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-12&engl=1}
}
@inproceedings {INPROC-2012-10,
   author = {Sebastian Wagner and Oliver Kopp and Frank Leymann},
   title = {{Towards Verification of Process Merge Patterns with Allen’s Interval Algebra}},
   booktitle = {Proceedings of the 4th Central-European Workshop on Services and their Composition (ZEUS 2012)},
   address = {Bamberg},
   publisher = {CEUR Workshop Proceedings},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--8},
   type = {Workshop Paper},
   month = {March},
   year = {2012},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2012-10/INPROC-2012-10.pdf,     http://zeus2012.pi.uni-bamberg.de/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Choreographies present how parties collaborate to achieve an agreed business objective. When companies are bought, their processes have to be in-sourced. Thereby, their part in a choreography has to be merged with the part of their acquiring business partner. Merging patterns may be applied to merge reoccurring activity combinations, such as send/receive. It has to be proven that each merge patterns keeps the relations of the original activities of the choreography. As a first step, we show by an example how the relations between activities may be expressed using the Allen calculus. We show for merging a synchronous message exchange, which relations have to be considered for validating an implementation of that merge.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-10&engl=1}
}
@inproceedings {INPROC-2012-09,
   author = {Vasilios Andrikopoulos and Christoph Fehling and Frank Leymann},
   title = {{Designing for CAP - The Effect of Design Decisions on the CAP Properties of Cloud-native Applications}},
   booktitle = {Proceedings of the 2nd International Conference on Cloud Computing and Services Science (CLOSER 2012); Porto, Portugal, April 18-21, 2012},
   address = {Porto, Portugal},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {April},
   year = {2012},
   keywords = {CAP Theorem; Cloud Patterns; Cloud-native Applications Design},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     D.2.11 Software Engineering Software Architectures,     H.3.4 Information Storage and Retrieval Systems and Software},
   contact = {vasilios.andrikopoulos@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The limitations of distributed systems to satisfy the combination of consistency, availability and network partitioning tolerance requirements are well-documented and formally proven. There is however a limited amount of works discussing the impact of these limitations on designing applications native to the Cloud. This work addresses this particular need by proposing an approach for considering these requirements while designing an application. Our contributions are therefore a methodology for Cloud-native application design which considers consistency, availability and network partitioning tolerance, and a framework instantiating this methodology by using design patterns and their realization solutions on the Cloud. We also show how the proposed methodology can be used in practice to design an application solution with desired properties.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-09&engl=1}
}
@inproceedings {INPROC-2012-08,
   author = {Steve Strauch and Uwe Breitenb{\"u}cher and Oliver Kopp and Frank Leymann and Tobias Unger},
   title = {{Cloud Data Patterns for Confidentiality}},
   booktitle = {Proceedings of the 2nd International Conference on Cloud Computing and Service Science (CLOSER'12)},
   publisher = {SciTePress},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {387--394},
   type = {Conference Paper},
   month = {April},
   year = {2012},
   keywords = {patterns; confidentiality; database layer; migration; distributed application architecture; cloud data store},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     D.2.11 Software Engineering Software Architectures,     H.3.4 Information Storage and Retrieval Systems and Software},
   contact = {a href=``http://www.iaas.uni-stuttgart.de/institut/mitarbeiter/strauch''Steve Strauch/ a},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Cloud computing enables cost-effective, self-service, and elastic hosting of applications in the Cloud. Applications may be partially or completely moved to the Cloud. When hosting or moving the database layer to the Cloud, challenges such as avoidance of disclosure of critical data have to be faced. The main challenges are handling different levels of confidentiality and satisfying security and privacy requirements. We provide reusable solutions in the form of patterns.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-08&engl=1}
}
@inproceedings {INPROC-2012-04,
   author = {Johanna Barzen and Frank Leymann and David Schumm and Matthias Wieland},
   title = {{Ein Ansatz zur Unterst{\"u}tzung des Kost{\"u}mmanagements im Film auf Basis einer Mustersprache}},
   booktitle = {Proceedings Modellierung 2012},
   publisher = {GI},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {0--16},
   type = {Conference Paper},
   month = {March},
   year = {2012},
   language = {German},
   cr-category = {H.1.2 User/Machine Systems,     H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Das Kost{\"u}m im Film ist ein komplexes Konstruktionsinstrument, welches der Charakterisierung der Figuren, des Raums und der Zeit dient. Recherche, Entwurf und Wissensmanagement von Kost{\"u}men werden derzeit meist mit Hilfe zeit-, kosten- und ressourcenintensiver Analyse von Datens{\"a}tzen in Microsoft Excel durchgef{\"u}hrt. Dar{\"u}ber hinausgehende Unterst{\"u}tzung durch IT-Werkzeuge beschr{\"a}nkt sich auf die einfache Dokumentation, Inventarisierung und Administration von Kost{\"u}men als Ganzes. In dieser Arbeit stellen wir einen ersten Ansatz hin zu einer IT-Unterst{\"u}tzung f{\"u}r das Kost{\"u}mmanagement vor. Dieser Ansatz basiert auf einer Mustersprache, welche die Modellierung und den Aufbau von Kost{\"u}men aus atomaren und zusammengesetzten Mustern erlaubt, sowie die Relationen von Kost{\"u}men und Mustern zum Ausdruck bringt. Darauf aufbauend kann ein IT-System implementiert werden, welches mittels Datenbanktechniken und Workflowsystemen das Management von Kost{\"u}men vereinfachen soll.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-04&engl=1}
}
@inproceedings {INPROC-2012-02,
   author = {Alexander Nowak and Tobias Binz and Frank Leymann and Daniel Schleicher and David Schumm and Sebastian Wagner},
   title = {{Ein Konzept zur Identifikation {\"o}kologisch nachhaltiger Verbesserungspotentiale unter B{\"u}rgerbeteiligung}},
   booktitle = {Tagungsband der Multikonferenz Wirtschaftsinformatik 2012},
   address = {Berlin},
   publisher = {Gito Verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1559--1570},
   type = {Conference Paper},
   month = {February},
   year = {2012},
   isbn = {978-3-942183-63-5},
   keywords = {Nachhaltigkeitsmanagement, Green IT, Pattern Identifikation, Green Patterns, B{\"u}rgerbeteiligung},
   language = {German},
   cr-category = {H.4.1 Office Automation},
   ee = {http://mkwi2012.de/downloads/MKWI2012_Tagungsband.pdf},
   contact = {alexander.nowak@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Die Optimierung von Abl{\"a}ufen zum Erhalt der Wettbewerbsf{\"a}higkeit ist ein fester Bestandteil heutiger Organisationen. Die immer vielf{\"a}ltigeren Anforderungen an Optimierungsvorhaben, sowie die steigende Komplexit{\"a}t der zu optimierenden Problemstellungen erfordert zum einen die Erschlie{\ss}ung neuer Wissensquellen und zum anderen die zielorientierte Nutzung geeigneter Verfahrensmuster aus fr{\"u}heren Problemstellungen. In dieser Arbeit wird am Beispiel der Identifikation {\"o}kologisch nachhaltiger Verbesserungspotentiale unter Nutzung von B{\"u}rgerbeteiligungen gezeigt, wie soziale Aspekte innerhalb von Optimierungsverfahren effizient eingesetzt und anschlie{\ss}end als strukturierte Verfahrensmuster wiederverwendbar gemacht werden k{\"o}nnen.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2012-02&engl=1}
}
@inproceedings {INPROC-2011-78,
   author = {Monika Weidmann and Modood Alvi and Falko Koetter and Frank Leymann and Thomas Renner and David Schumm},
   title = {{Business Process Change Management based on Process Model Synchronization of Multiple Abstraction Levels}},
   booktitle = {Proceedings of SOCA},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--4},
   type = {Conference Paper},
   month = {December},
   year = {2011},
   doi = {10.1109/SOCA.2011.6166253},
   keywords = {Model Synchronization; Abstraction Levels; Change Propagation; Business Process Modelling},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Management of business processes is typically performed on multiple levels, each with different granularity, language constructs, and abstraction. Starting from an initial sketch of the activities to be performed, several refinements are made to entirely specify the business process, its artifacts, and participants. Then, information relevant for process execution can be added to enable efficient automation in the context of a service-oriented architecture (SOA). However, dealing with changes initiated by business or technology is a key difficulty in this approach. If change management is not performed properly then process models become out of sync which results in losing the alignment of business and IT. To address this challenge, we propose a synchronization method based on model element correspondence that considers change management between process models on different abstraction levels. We show how synchronization can be established and changes are propagated using a change queue for synchronization continuity. Finally we present a prototypical implementation of the key concepts.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-78&engl=1}
}
@inproceedings {INPROC-2011-77,
   author = {Michael Reiter and Uwe Breitenb{\"u}cher and Schahram Dustdar and Dimka Karastoyanova and Frank Leymann and Hong-Linh Truong},
   title = {{A Novel Framework for Monitoring and Analyzing Quality of Data in Simulation Workflows}},
   booktitle = {2011 Seventh IEEE International Conference on eScience},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {December},
   year = {2011},
   language = {English},
   cr-category = {H.4.1 Office Automation,     I.6.7 Simulation Support Systems},
   contact = {Michael Reiter Michael.Reiter@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In recent years scientific workflows have been used for conducting data-intensive and long running simulations. Such simulation workflows have processed and produced different types of data whose quality has a strong influence on the final outcome of simulations. Therefore being able to monitor and analyze quality of this data during workflow execution is of paramount importance, as detection of quality problems will enable us to control the execution of simulations efficiently. Unfortunately, existing scientific workflow execution systems do not support the monitoring and analysis of quality of data for multi-scale or multi-domain simulations. In this paper, we examine how quality of data can be comprehensively measured within workflows and how the measured quality can be used to control and adapt running workflows. We present a quality of data measurement process and describe a quality of data monitoring and analysis framework that integrates this measurement process into a workflow management system.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-77&engl=1}
}
@inproceedings {INPROC-2011-75,
   author = {Tobias Binz and Frank Leymann and David Schumm},
   title = {{CMotion: A Framework for Migration of Applications into and between Clouds}},
   booktitle = {Proceedings of the 2011 IEEE International Conference on Service-Oriented Computing and Applications (SOCA)},
   publisher = {IEEE Computer Society Conference Publishing Services},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {December},
   year = {2011},
   doi = {10.1109/SOCA.2011.6166250},
   keywords = {application migration; service management; cloud computing; composite applications},
   language = {English},
   cr-category = {K.6 Management of Computing and Information Systems,     D.2.12 Software Engineering Interoperability},
   contact = {a href=``http://www.iaas.uni-stuttgart.de/institut/mitarbeiter/binz''Tobias Binz/ a},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The number of applications and services hosted in the cloud grows steadily, because of significant advantages in cost, flexibility, and scale compared to traditional IT. However, major difficulties in this field are (i) the migration of existing applications into the cloud and (ii) the increasing vendor lock-in which denotes the inability to leave a certain cloud provider without significant effort. Current approaches do not offer a holistic solution: Either they require the user to provide the application in a certain standardized way or they are only able to migrate one specific type of component. As a consequence, the migration of composite applications with different types of components is not supported. To overcome this limitation we propose the Cloud Motion Framework (CMotion) which leverages existing application models and provides support to migrate composite applications into and between clouds. Based on the application model, the framework evaluates alternative ways to host each component. CMotion assumes that the dependencies of components are modeled explicitly and the components are self-contained.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-75&engl=1}
}
@inproceedings {INPROC-2011-72,
   author = {Daniel Schleicher and Frank Leymann and Patrick Schneider and David Schumm and Tamara Wolf},
   title = {{An Approach to Combine Data-Related and Control-Flow-Related Compliance Rules}},
   booktitle = {Proceedings of SOCA},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {December},
   year = {2011},
   doi = {10.1109/SOCA.2011.6166212},
   keywords = {Compliance, LTL, constraint, pattern, business process},
   language = {German},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Compliance of IT-enabled business processes is a research area gaining more and more attraction for enterprises today. Many enterprises are on the gap of installing workflow systems within their premises. During this process they need to make sure that several regulations, coming from governments or enterprise-internal institutions, are obeyed. We argue that the compliance regulations, enterprises are faced with today, can be built using a number of atomic compliance requirements. We studied literature and identified new atomic requirements in our work with industrial use case partners taking part in research projects founded by the European Union, as well as projects with customers that face the same challenges. The atomic compliance rules, we identified, can be divided into two groups, data-related and control-flow-related compliance rules. The main contribution of this paper is a collection of patterns implementing complex compliance rules which consist of atomic control-flow related and data-related compliance rules. We show how these atomic rules must be applied to a business process in order to implement the desired behaviour, intended by a complex compliance rule. We extended an existing collection of recurring atomic compliance rules with a new set of data-related compliance rules. These compliance rules contain variabilities which need to be filled when they are applied to a business process model.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-72&engl=1}
}
@inproceedings {INPROC-2011-71,
   author = {Steve Strauch and Oliver Kopp and Frank Leymann and Tobias Unger},
   title = {{A Taxonomy for Cloud Data Hosting Solutions}},
   booktitle = {Proceedings of the International Conference on Cloud and Green Computing (CGC '11)},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {577--584},
   type = {Conference Paper},
   month = {December},
   year = {2011},
   doi = {10.1109/DASC.2011.106},
   keywords = {cloud data hosting solution; taxonomy; distributed application architecture; database layer; cloud computing},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     D.2.11 Software Engineering Software Architectures,     H.3.4 Information Storage and Retrieval Systems and Software},
   contact = {steve.strauch@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Cloud computing allows reducing capital expenditure by using resources on demand. We investigate how to build a database layer in the Cloud and present pure and hybrid Cloud data hosting solutions. The solutions are organized in a taxonomy. The properties used for organization are: application layer, deployment model, location, service model, data store type, and compatibility. Using the taxonomy, existing Cloud data hosting solutions are categorized.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-71&engl=1}
}
@inproceedings {INPROC-2011-69,
   author = {Alexander Nowak and Frank Leymann and David Schumm},
   title = {{The Differences and Commonalities between Green and Conventional Business Process Management}},
   booktitle = {Proceedings of the International Conference on Cloud and Green Computing, CGC 2011},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {December},
   year = {2011},
   doi = {10.1109/DASC.2011.105},
   keywords = {Green IT; Green Business Process Management; BPM Lifecycle; BPM Architecture},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Environmentally-aware resource usage has become an important aspect for today’s industries, governments, and organizations. Customer demands, legal requirements, and financial aspects force organizations to rethink and reorganize their existing structures and business processes. Along with an increasing adoption of Business Process Management (BPM) in organizations, efforts are being made to also enable a green rethinking and change of BPM. However, in order to be capable of performing business in a green manner, the “delta” has to be known that distinguishes green business process management from the conventional one. In this paper, we investigate key perspectives of conventional BPM and compare them to requirements originating from an environmental perspective. The key perspectives we refer to are the business process lifecycle, key performance indicators, BPM architectures, and business and strategy. We highlight aspects that need to be extended, newly developed, or refined in order to achieve a holistic green BPM approach.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-69&engl=1}
}
@inproceedings {INPROC-2011-68,
   author = {Adina Sirbu and Annapaola Marconi and Marco Pistore and Hanna Eberle and Frank Leymann and Tobias Unger},
   title = {{Dynamic Composition of Pervasive Process Fragments}},
   booktitle = {Proceedings of the IEEE International Conference on Web Services, ICWS 2011,Washington, DC, USA, July 4-9, 2011},
   editor = {IEEE Computer Society},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {73--80},
   type = {Conference Paper},
   month = {July},
   year = {2011},
   isbn = {978-0-7695-4463-2},
   doi = {10.1109/ICWS.2011.70},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://doi.ieeecomputersociety.org/10.1109/ICWS.2011.70},
   contact = {Tobias Unger unger@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {A critical aspect for pervasive computing is the possibility to discover and use process knowledge at run time depending on the specific context. This can be achieved by using an underlying service-based application and exploiting its features in terms of dynamic service discovery, selection, and composition. Pervasive process fragments represent a service-based tool that allows to model incomplete and contextual knowledge. We provide a solution to automatically compose such fragments into complete processes, according to a specific context and specific goals. We compute the solution by encoding process knowledge, domain knowledge and goals into an AI planning problem. We evaluate our approach on different scenarios stress testing the main characteristics of pervasive process fragments.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-68&engl=1}
}
@inproceedings {INPROC-2011-67,
   author = {Daniel Schleicher and J{\"o}rg Niem{\"o}ller and Frank Leymann and Konstantinos Vandikas and Roman Levenshteyn},
   title = {{Towards a Service Composition Language for Heterogeneous Service Environments}},
   booktitle = {Proceedings of the ICIN Conference 2011},
   publisher = {IEEE Xplore},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {121--126},
   type = {Conference Paper},
   month = {October},
   year = {2011},
   doi = {10.1109/ICIN.2011.6081059},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In this paper we provide an outline and characteristics of a language that allows the design of compositions within a heterogeneous service landscape. Heterogeneous refers to services from various industries and application domains like for example telecommunication, enterprise, web 2.0 and general IT. The language shall enable to use services from all these domains within a single service composition. We propose general requirements for this new language and we also offer an analysis of existing languages and their specific application domains. Finally, we discuss and propose extensions to an already existing standardized workflow language that enables heterogeneous compositions.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-67&engl=1}
}
@inproceedings {INPROC-2011-66,
   author = {Christoph Fehling and Frank Leymann and Ralph Retter and David Schumm and Walter Schupeck},
   title = {{An Architectural Pattern Language of Cloud-based Applications}},
   booktitle = {Proceedings of the 18th Conference on Pattern Languages of Programs, PLoP 2011},
   publisher = {ACM},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--11},
   type = {Conference Paper},
   month = {October},
   year = {2011},
   doi = {10.1145/2578903.2579140},
   language = {English},
   cr-category = {H.4.1 Office Automation,     C.2.4 Distributed Systems,     D.2.2 Software Engineering Design Tools and Techniques,     D.2.3 Software Engineering Coding Tools and Techniques},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Cloud computing has drastically changed the way in which IT resources can be consumed. The properties of clouds – elasticity, pay-per-use, and standardization of the runtime infrastructure – enable cloud providers and users alike to benefit from economies of scale, faster provisioning times, and reduced runtime costs. However, to achieve these benefits, application architects and developers have to respect the characteristics of the cloud environment. To reduce the complexity of cloud application architecture and design, we propose a pattern-based approach for cloud application architecture and development. We defined a pattern format to describe the principles of cloud computing, available cloud offerings, and cloud application architectures. Based on this format we developed an architectural pattern language of cloud-based applications. Through interrelation of patterns for cloud offering descriptions and cloud application architectures, developers are guided during the identification of patterns applicable to their problems. We cover the proceeding how we identified patterns, give an overview of previously discovered patterns, and introduce one new pattern. Further, we propose a framework for the organizations of patterns and the guidance of developers during their instantiation.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-66&engl=1}
}
@inproceedings {INPROC-2011-65,
   author = {Alexander Nowak and Frank Leymann and Daniel Schleicher and David Schumm and Sebastian Wagner},
   title = {{Green Business Process Patterns}},
   booktitle = {Proceedings of the 18th Conference on Pattern Languages of Programs, PLoP 2011},
   publisher = {ACM},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {October},
   year = {2011},
   doi = {10.1145/2578903.2579144},
   keywords = {Green IT; Green Patterns; Green Business Process Management; Environmental Impact},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {To ensure their competitive advantage an increasing number of organizations adopt business process management for design, automation, and analysis of their business processes. In order to reduce cost, improve quality, save time, and increase flexibility, techniques for business process improvement and re-engineering are applied. Improving the environmental impact of a business process is a new challenge organizations are faced with. However, current approaches and techniques for business process optimization do not cover the ecological dimension explicitly. In this paper, we propose patterns which describe good solutions for green business process design to address this gap from a business perspective. The patterns are described independently from concrete business process modeling languages and execution environments in order to provide a broad applicability of the patterns within different scenarios. In addition to the patterns, we discuss the general usability of the patterns based on different aspects relevant to an organization.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-65&engl=1}
}
@inproceedings {INPROC-2011-63,
   author = {Sam Guinea and Gabor Kecskemeti and Annapaola Marconi and Branimir Wetzstein},
   title = {{Multi-layered Monitoring and Adaptation}},
   booktitle = {Proceedings of the Ninth International Conference on Service Oriented Computing (ICSOC 2011); Paphos, Cyprus, December 5-8, 2011},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {December},
   year = {2011},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Service-based applications have become more and more multi-layered in nature, as we tend to build software as a service on top of infrastructure as a service. Most existing SOA monitoring and adaptation techniques address layer-specific issues. These techniques, if used in isolation, cannot deal with real-world domains, where changes in one layer often affect other layers, and information from multiple layers is essential in truly understanding problems and in developing comprehensive solutions. In this paper we propose a framework that integrates layer specific monitoring and adaptation techniques, and enables multi-layered control loops in service-based systems. The proposed approach is evaluated on a medical imaging procedure for Computed Tomography (CT) Scans, an e-Health scenario characterized by strong dependencies between the software layer and infrastructural resources.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-63&engl=1}
}
@inproceedings {INPROC-2011-62,
   author = {Michele Mancioppi and Olha Danylevych and Dimka Karastoyanova and Frank Leymann},
   title = {{Towards Classification Criteria for Process Fragmentation Techniques}},
   booktitle = {Proceedings of BPD 2011 (colocated with BPM 2011)},
   publisher = {Springer Verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Workshop Paper},
   month = {December},
   year = {2011},
   keywords = {Process fragments, process fragmentation, process improvement techniques},
   language = {English},
   cr-category = {D.2.2 Software Engineering Design Tools and Techniques,     H.4.1 Office Automation},
   contact = {michele.mancioppi@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Process fragmentation is the foundation of many state-of-the-art techniques for supporting management, reuse and change of process models. Such techniques vary greatly in terms of which types of processes they are applicable to, what they aim at accomplishing, how they define the resulting process fragments, etc. The comparison, analysis, reuse and selection of the available process fragmentation techniques are hindered by the lack of a common terminology and classification criteria, and by the large discrepancy in the characteristics that are covered when presenting novel fragmentation techniques. This work starts addressing this issue by investigating classification criteria for process fragmentation techniques based on the “seven Ws”, namely Why, What, When, Where, Who, Which, and hoW. The presented classification criteria are applied to some of the process fragmentation approaches available in the literature. In addition to enabling the classification of fragmentation techniques, the classification criteria here presented form a “check-list” for authors of future works in the field of process fragmentation.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-62&engl=1}
}
@inproceedings {INPROC-2011-60,
   author = {Oliver Kopp and Frank Leymann and Sebastian Wagner},
   title = {{Modeling Choreographies: BPMN 2.0 versus BPEL-based Approaches}},
   booktitle = {Enterprise Modelling and Information Systems Architectures - EMISA 2011},
   publisher = {Gesellschaft f{\"u}r Informatik e.V. (GI)},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Informatics},
   type = {Workshop Paper},
   month = {September},
   year = {2011},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://www.wiso.uni-hamburg.de/conferences/emisa2011/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Choreographies capture the collaboration aspects between two or more processes. Explicit choreography notations have been included in the upcoming version 2.0 of the Business Process Model and Notation language (BPMN 2.0). This paper presents a first evaluation of the choreography modeling capabilities of BPMN 2.0 and presents a summary of the evaluation of BPEL-based approaches. The result is that BPMN 2.0 does not support reference passing and is tightly tied to technical configurations.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-60&engl=1}
}
@inproceedings {INPROC-2011-58,
   author = {Sebastian Wagner and Oliver Kopp and Frank Leymann},
   title = {{Towards Choreography-based Process Distribution In The Cloud}},
   booktitle = {Proceedings of the 2011 IEEE International Conference on Cloud Computing and Intelligence Systems},
   address = {Bejing, China},
   publisher = {IEEE Xplore},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {490--494},
   type = {Conference Paper},
   month = {September},
   year = {2011},
   doi = {10.1109/CCIS.2011.6045116},
   language = {English},
   cr-category = {H.4.1 Office Automation,     H.5.3 Group and Organization Interfaces},
   contact = {sebastian.wagner@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Choreographies provide means to describe collaborations. Each partner runs its own processes. To reduce the amount of data exchanged and to save resources, part of the choreography can be run on a community cloud. We show how private parts of a choreography can still be run on-premise and how non-private parts can be merged to make use of the cloud infrastructure.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-58&engl=1}
}
@inproceedings {INPROC-2011-56,
   author = {Mirko Sonntag and Dimka Karastoyanova},
   title = {{Enforcing the Repeated Execution of Logic in Workflows}},
   booktitle = {Proceedings of the 1st International Conference on Business Intelligence and Technology (BUSTECH 2011), Rome, Italy, 2011},
   publisher = {IARIA},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--6},
   type = {Conference Paper},
   month = {September},
   year = {2011},
   keywords = {Service composition; Workflow adaptability; Iteration; Re-execution},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   contact = {Mirko Sonntag: sonntag@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The repeated execution of workflow logic is a feature needed in many situations. Repetition of activities can be modeled with workflow constructs (e.g., loops) or external workflow configurations, or can be triggered by a user action during workflow execution. While the first two options are state of the art in the workflow technology, the latter is currently insufficiently addressed in literature and practice. We argue that a manually triggered rerun operation enables both business users and scientists to react to unforeseen problems and thus improves workflow robustness, allows scientists steering the convergence of scientific results, and facilitates an explorative workflow development as required in scientific workflows. In this paper, we therefore formalize operations for the repeated enactment of activities—for both iteration and re-execution. Starting point of the rerun is an arbitrary, manually selected activity. Since we define the operations on a meta-model level, they can be implemented for different workflow languages and engines.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-56&engl=1}
}
@inproceedings {INPROC-2011-52,
   author = {Mirko Sonntag and Sven Hotta and Dimka Karastoyanova and David Molnar and Siegfried Schmauder},
   title = {{Using Services and Service Compositions to Enable the Distributed Execution of Legacy Simulation Applications}},
   booktitle = {Towards a Service-Based Internet, Proceedings of the 4th European Conference ServiceWave 2011, Poznan, Poland, 2011},
   editor = {W. Abramowicz and I.M. Llorente and M. Surridge and A. Zisman and J. Vayssi{\`e}re},
   publisher = {Springer-Verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--12},
   type = {Conference Paper},
   month = {October},
   year = {2011},
   keywords = {Service compositions; Simulation workflows; distributed simulations; BPEL; Web services},
   language = {English},
   cr-category = {H.4.1 Office Automation,     I.6.7 Simulation Support Systems},
   contact = {Mirko Sonntag sonntag@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In the field of natural and engineering science, computer simulations play an increasingly important role to explain or predict phenomena of the real world. Although the software landscape is crucial to support scientists in their every day work, we recognized during our work with scientific institutes that many simulation programs can be considered legacy monolithic applications. They are developed without adhering to known software engineering guidelines, lack an acceptable software ergonomics, run sequentially on single workstations and require tedious manual tasks. We are convinced that SOA concepts and the service composition technology can help to improve this situation. In this paper we report on the results of our work on the service- and service composition-based re-engineering of a legacy scientific application for the simulation of the ageing process in copper-alloyed. The underlying general concept for a distributed, service-based simulation infrastructure is also applicable to other scenarios. Core of the concept is a resource manager that steers server work load and handles simulation data.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-52&engl=1}
}
@inproceedings {INPROC-2011-50,
   author = {Mirko Sonntag and Dimka Karastoyanova},
   title = {{Compensation of Adapted Service Orchestration Logic in BPEL’n’Aspects}},
   booktitle = {Proceedings of the 9th International Conference on Business Process Management (BPM 2011), Clermont-Ferrand, France, 2011},
   publisher = {Springer-Verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--16},
   type = {Conference Paper},
   month = {August},
   year = {2011},
   keywords = {Workflow; Service Composition; BPEL; Compensation; Aspect-orientation; Adaptability},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   contact = {sonntag@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {BPEL’n’Aspects is a non-intrusive mechanism for adaptation of control flow of BPEL processes based on the AOP paradigm. It relies on Web service standards to weave process activities in terms of aspects into BPEL processes. This paper is a logical continuation of the BPEL’n’Aspects approach. Its main objective is to enable compensation of weaved-in Web service invocations (activities) in a straightforward manner. We present (1) requirements on a mechanism for compensation of weaved-in process activities; (2) the corresponding concepts and mechanisms to meet these requirements; (3) an example scenario to show the applicability of the approach; and (4) a prototypical implementation to prove the feasibility of the solution. This work represents an improvement in the applicability of this particular adaptation approach since processes in production need the means to compensate actions that are included into processes as result of an adaptation step, too. The concept is generic and hence can also be used by other approaches that adapt control flow.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-50&engl=1}
}
@inproceedings {INPROC-2011-48,
   author = {Mirko Sonntag and Katharina G{\"o}rlach and Dimka Karastoyanova and Frank Leymann and Polina Malets and David Schumm},
   title = {{Views on Scientific Workflows}},
   booktitle = {Proceedings of the 10th International Conference on Perspectives in Business Informatics Research (BIR 2011), 2011},
   publisher = {Springer-Verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Business Information Processing},
   volume = {90},
   pages = {321--335},
   type = {Conference Paper},
   month = {October},
   year = {2011},
   doi = {10.1007/978-3-642-24511-4_25},
   keywords = {Process Views, BPEL, Web Services, SOA, Simulation Workflows, Scientific Workflows.},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   contact = {sonntag@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Workflows are becoming more and more important in e-Science due to the support they provide to scientists in computer simulations, experiments and calculations. Our experiences with workflows in this field and the literature show that scientific workflows consist of a large number of related information. This information is difficult to deal with in a single perspective and has changing importance to scientists in the different workflow lifecycle phases. In this paper we apply viewing techniques known from business process management to (service-based) scientific workflows to address these issues. We describe seven of the most relevant views and point out realization challenges. We argue that the selected views facilitate the handling of workflows to scientists and add further value to scientific workflow systems. An implementation of a subset of the views based on Web services and BPEL shows the feasibility of the approach. The presented work has the goal to increase additionally the acceptance of the workflow technology in e-Science.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-48&engl=1}
}
@inproceedings {INPROC-2011-45,
   author = {Matthias Wieland and Daniela Nicklas and Frank Leymann},
   title = {{Context Model for Representation of Business Process Management Artifacts}},
   booktitle = {International Proceedings of Economics Development and Research: IPEDR},
   editor = {Chun Hua Lin and Ming Zhang},
   publisher = {IACSIT PRESS},
   institution = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   series = {Economics and Business Information},
   volume = {9},
   pages = {46--51},
   type = {Conference Paper},
   month = {May},
   year = {2011},
   isbn = {978-981-08-8869-5},
   issn = {2010-4626},
   keywords = {business process management; workflows; context-awareness; human tasks; services},
   language = {English},
   cr-category = {H.1.2 User/Machine Systems,     H.4.1 Office Automation},
   ee = {http://www.ipedr.com/vol9.htm},
   contact = {wieland@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Context-aware systems adapt their functionality and behavior to the user and his or her situation. To do so, they need context information about the user’s environment, e.g., about different kinds of real world objects. To model and manage context information, many systems have been developed. An important part of context that is often neglected is the state and context of the applications that users are currently executing. The contribution of this paper is to present an extension for a standard context model that allows the representation of the context of workflow based applications. By that, business process management environments are enabled to annotate their context and provide it for other context-aware applications and users.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-45&engl=1}
}
@inproceedings {INPROC-2011-42,
   author = {Jorge Minguez and Peter Reimann and Sema Zor},
   title = {{Event-driven Business Process Management in Engineer-to-Order Supply Chains}},
   booktitle = {Proceedings of the 15th International Conference on Computer Supported Cooperative Work in Design},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--8},
   type = {Conference Paper},
   month = {June},
   year = {2011},
   keywords = {Event-driven Architecture; Service-oriented Architecture; SOA; EDA; Engineer-to-Order; ETO; Supply chain},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures,     D.2.13 Software Engineering Reusable Software},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Integration efforts in today’s manufacturing environments tend to enable service-based communication interfaces between enterprise and manufacturing systems. Constantly changing business conditions demand a high level of flexibility in business processes as well as an adaptive and fully interoperable IT infrastructure. The principles of reusability and loosely-coupled services have driven Service Oriented Architecture (SOA) to become the most used paradigm for software design at the business level. In a manufacturing environment, event-driven architectures (EDA) are often employed for managing information flows across different production systems. The timely propagation of business-relevant events is a fundamental requirement in Engineer-to-Order (ETO) enterprises, which require a high level of transparency in their supply chains. Agility is one of the top priorities for ETO manufacturers in order to react to turbulent scenarios. Therefore, the main challenge for ETO supply chains is to identify and propagate events across the ETO logistics network and integrate these into the manufacturer business processes. We present how an existing service-oriented integration platform for manufacturing can be used to fill the gap between EDA-based manufacturing environments of an ETO supply chain and SOA-based manufacturer business processes. In this paper, we discuss the benefits of the Business Process Execution Language (BPEL) as vehicle for this integration. The adoption of BPEL will enable an efficient and effective reaction to turbulent manufacturing scenarios in an ETO supply chain.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-42&engl=1}
}
@inproceedings {INPROC-2011-38,
   author = {Monika Weidmann and Falko Koetter and Thomas Renner and David Schumm and Frank Leymann and Daniel Schleicher},
   title = {{Synchronization of Adaptive Process Models Using Levels of Abstraction}},
   booktitle = {Proceedings of the 4th International Workshop on Evolutionary Business Processes (EVL-BP 2011)},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {174--183},
   type = {Workshop Paper},
   month = {August},
   year = {2011},
   doi = {10.1109/EDOCW.2011.24},
   keywords = {Adaptive Business Processes; Sychronization; Abstraction Levels; Business Process Management},
   language = {German},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Today many companies use several technologies, modeling languages, and software tools for designing, analyzing, and executing their business processes. The need for adapting processes to new requirements, to reuse parts of processes, and to involve different stakeholders in the process design leads to process changes on multiple process models of different granularity and level of abstraction. These changes cause a need for process models on different abstraction levels to be synchronized in order to avoid inconsistencies. To bridge the resulting Business IT gap, we introduce an approach which supports the creation and adaptation of business processes on different abstraction levels based on reusable process building blocks. The advantage of the approach is that changes of the process can be driven by IT and Business in the same manner, though on different levels of abstraction. In addition to the methodology for this approach, we define reusable process building blocks, describe sychronization mechanisms, and propose a supporting infrastructure. We show the application of these concepts in a real world case study.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-38&engl=1}
}
@inproceedings {INPROC-2011-35,
   author = {David Schumm and Jiayang Cai and Christoph Fehling and Dimka Karastoyanova and Frank Leymann and Monika Weidmann},
   title = {{Composite Process View Transformation}},
   booktitle = {Proceedings of the 12th International Conference on Electronic Commerce and Web Technologies},
   publisher = {Springer-Verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Business Information Processing},
   volume = {85},
   pages = {52--63},
   type = {Conference Paper},
   month = {August},
   year = {2011},
   isbn = {978-3-642-23013-4},
   doi = {10.1007/978-3-642-23014-1_5},
   keywords = {Process View, Service Composition, BPM},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     D.2.2 Software Engineering Design Tools and Techniques,     H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The increasing complexity of processes used for design and execution of critical business activities demands novel techniques and technologies. Process viewing techniques have been proposed as a means to abstract from details, summarize and filter out information, and customize the visual appearance of a process to the need of particular stakeholders. However, composition of process view transformations and their provisioning as a service to enable their usage in various different scenarios is currently not discussed in research. In this paper, we present a lightweight, service-oriented approach to compose modular process viewing functions to form complex process view transformations which can be offered as a service. We introduce a concept and an architectural framework to generate process view service compositions automatically with focus on usability. Furthermore, we discuss key aspects regarding the implementation as well as different scenarios where process view services and their compositions are needed.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-35&engl=1}
}
@inproceedings {INPROC-2011-34,
   author = {Christoph Fehling and Ralf Konrad and Frank Leymann and Ralph Mietzner and Michael Pauly and David Schumm},
   title = {{Flexible Process-based Applications in Hybrid Clouds}},
   booktitle = {Proceedings of the 2011 IEEE International Conference on Cloud Computing (CLOUD 2011)},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--8},
   type = {Conference Paper},
   month = {July},
   year = {2011},
   doi = {10.1109/CLOUD.2011.37},
   keywords = {Application Customization, Self-service, Orchestration, Composite Application, Provisioning, Cloud},
   language = {English},
   cr-category = {C.0 Computer Systems Organization, General,     C.2.4 Distributed Systems,     D.2.2 Software Engineering Design Tools and Techniques,     D.2.3 Software Engineering Coding Tools and Techniques,     D.2.7 Software Engineering Distribution, Maintenance, and Enhancement},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Cloud applications target large costumer groups to leverage economies of scale. To increase the number of customers, a flexible application design is of major importance. It enables customers to adjust the application to their individual needs in a self-service manner. In this paper, we classify the required variability of these flexible applications: data variability – changes to handled data structures; functional variability – changes to the processes that the application supports; user interface variability – changes to the appearance of the application; provisioning variability – the ability of the application to be deployed in different runtime environments. Existing and new technologies and tools are leveraged to realize these classes of variability. Further, we cover architectural principles to follow during the design of flexible cloud applications and we introduce an abstract architectural pattern to enable data variability.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-34&engl=1}
}
@inproceedings {INPROC-2011-33,
   author = {Alexander Nowak and Frank Leymann and David Schumm and Branimir Wetzstein},
   title = {{An Architecture and Methodology for a Four-Phased Approach to Green Business Process Reengineering}},
   booktitle = {Proceedings of the 1st International Conference on ICT as Key Technology for the Fight against Global Warming - ICT-GLOW 2011},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science},
   volume = {6868},
   pages = {150--164},
   type = {Conference Paper},
   month = {August},
   year = {2011},
   doi = {10.1007/978-3-642-23447-7_14},
   keywords = {Business Processes, Process Views, Process Monitoring, Adaptation, Environmental Impact, Green Business Process Reengineering},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Sustainability and responsible resource exposure has become a major issue in everyday life. Government, customers, and increasing social responsibility force more and more organizations to positively optimize their environmental impact towards a better, livable planet. In this paper we propose a four-layered architecture and corresponding four-phased methodology to enable organizations to (1) define ecological characteristics, (2) sense and measure these ecological characteristics, (3) identify, localize and visualize their environmental impact, and (4) help them to develop appropriate adaptation strategies in order to optimize their environmental impact without neglecting the organization’s competitiveness.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-33&engl=1}
}
@inproceedings {INPROC-2011-32,
   author = {Olha Danylevych and Christos Nikolaou and Frank Leymann},
   title = {{A Framework of Views on Service Networks Models}},
   booktitle = {EOMAS 2011},
   address = {Stuttgart},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--17},
   type = {Workshop Paper},
   month = {August},
   year = {2011},
   keywords = {Service networks; View projection; View aggregation},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   contact = {olha.danylevych@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Interdependency is one of the constants of business. Businesses form complex networks for the exchanging of goods and services. Service networks models represent the interconnections among companies, their parts and individuals in terms of services that are provided and consumed. A service network model is a representation of these interconnections. Due to the size of nowadays service networks, their models tend to grow very large. The effective management of service network models requires methods to limit the amount of data presented on the basis of what is needed. This paper identifies a hierarchy of views on service network models, namely offering-centric views, participant views and multilateral views. The offering-centric views focus on one service that is offered by one participant. Participant views present the entirety of the data related to one participant. Multilateral views represent the data regarding a set of participants. We identify the correlations between these views and the mechanisms to aggregate and project them from each other and from service network models. The concepts and mechanisms represented in this paper are explained on a running example based on the automotive industry.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-32&engl=1}
}
@inproceedings {INPROC-2011-29,
   author = {Daniel Schleicher and Christoph Fehling and Stefan Grohe and Frank Leymann and Alexander Nowak and Patrick Schneider and David Schumm},
   title = {{Compliance Domains: A Means to Model Data-Restrictions in Cloud Environments}},
   booktitle = {Enterprise Distributed Object Computing Conference (EDOC)},
   publisher = {IEEE Xplore},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {257--266},
   type = {Conference Paper},
   month = {August},
   year = {2011},
   doi = {10.1109/EDOC.2011.22},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {It is crucial for enterprises to execute business operations in a compliant way. This is especially true for ITdriven business processes as enterprises may face considerable fines when violating laws and regulation in their business processes. Through the advent of cloud computing, a new dimension of compliance requirements within the research area of compliant business process design has emerged. Datasovereignty is one of the major compliance concerns enterprises have to deal with when moving applications and data to the cloud. Enterprises are fully responsible for their data, also when the data is not present within their IT premises anymore. This lead to the policy that specific data must not leave the IT premises of the enterprise. In this paper we present an approach to support the human process designer in modelling compliant business processes. We are focusing on compliance requirements which have to be considered in the field of cloud computing. These requirements have been created to meet laws and regulations. These laws and regulations are considering data which is sent around between countries, for example. Considering the characteristics of these requirements, we deal with data-centric compliance rules here.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-29&engl=1}
}
@inproceedings {INPROC-2011-28,
   author = {Mirko Sonntag and Sven Hotta and Dimka Karastoyanova and David Molnar and Siegfried Schmauder},
   title = {{Workflow-Based Distributed Environment For Legacy Simulation Applications}},
   booktitle = {Proceedings of the 6th International Conference on Software and Data Technologies (ICSOFT 2011), Poster Paper},
   publisher = {SciTePress Digital Library},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {91--94},
   type = {Workshop Paper},
   month = {July},
   year = {2011},
   doi = {10.5220/0003444400910094},
   keywords = {Simulation workflows; distributed simulations; BPEL; Web services; Monte-Carlo},
   language = {English},
   cr-category = {H.4.1 Office Automation,     I.6.7 Simulation Support Systems},
   contact = {Mirko.Sonntag@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Computer simulations play an increasingly important role to explain or predict phenomena of the real world. We recognized during our work with scientific institutes that many simulation programs can be considered legacy applications with low software ergonomics, usability, and hardware support. Often there is no GUI and tedious manual tasks have to be conducted. We are convinced that the information technology and software engineering concepts can help to improve this situation to a great extent. In this poster presentation we therefore propose a concept of a simulation environment for legacy scientific applications. Core of the concept are simulation workflows that enable a distributed execution of former monolithic programs and a resource manager that steers server work load and handles data. As proof of concept we implemented a Monte-Carlo simulation of precipitations in copper-alloyed iron and tested it with real data.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-28&engl=1}
}
@inproceedings {INPROC-2011-21,
   author = {Falko K{\"o}tter and Monika Weidmann and Daniel Schleicher},
   title = {{Guaranteeing Soundness of adaptive Business Processes using ABIS}},
   booktitle = {14th International Conference, BIS 2011, Poznan, Poland, June 15-17, 2011, Proceedings},
   editor = {Witold Abramowicz and Robert Tolksdorf},
   address = {Korb},
   publisher = {Springer Verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--12},
   type = {Conference Paper},
   month = {June},
   year = {2011},
   keywords = {BPMN, Business process management},
   language = {German},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The Internet of Services necessitates ad-hoc collaboration of companies in business processes. Each collaboration requires speci c adjustments of the underlying process. While adapting these variable processes with multiple parties, a need for guaranteeing the soundness of business process variants arises. In this paper we extend the ABIS approach of adaptive business process modeling with soundness concepts and implement them in a prototype.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-21&engl=1}
}
@inproceedings {INPROC-2011-18,
   author = {Sema Zor and Frank Leymann and David Schumm},
   title = {{A Proposal of BPMN Extensions for the Manufacturing Domain}},
   booktitle = {Proceedings of the 44th CIRP Conference on Manufacturing Systems (ICMS 2011); Madison, Wisconsin, June 1-3, 2011},
   publisher = {-},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--6},
   type = {Conference Paper},
   month = {January},
   year = {2011},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://conferencing.uwex.edu/conferences/cirp2011/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The manufacturing domain can be characterized by the concepts of product, process and resource. The coordination of humans, machines and materials is needed to attain a desired product by using knowledge, time, money and energy optimally. Business processes define such coordination. Business Process Model and Notation (BPMN) is an industry standard for modeling business processes. This standard is not being applied to the manufacturing domain so far. In this paper, we propose BPMN extensions to support process modeling in the manufacturing domain, especially the modeling of production processes. We motivate and justify our proposed extensions by an exemplary assembly process.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-18&engl=1}
}
@inproceedings {INPROC-2011-15,
   author = {Oliver Kopp and Frank Leymann and David Schumm and Tobias Unger},
   title = {{On BPMN Process Fragment Auto-Completion}},
   booktitle = {Proceedings of the 3rd Central-European Workshop on Services and their Composition (ZEUS 2011)},
   editor = {Daniel Eichhorn and Agnes Koschmider and Huayu Zhang},
   publisher = {CEUR-WS.org},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {CEUR Workshop Proceedings},
   volume = {705},
   pages = {58--64},
   type = {Workshop Paper},
   month = {March},
   year = {2011},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://zeus2011.aifb.kit.edu/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Process fragments provide reusable granules of business processes to enable process modeling based on existing knowledge. Current verification tools cannot deal with BPMN process fragments and support complete BPMN processes only. To enable verification for BPMN process fragments, we sketch how a single BPMN fragment can be completed to a BPMN process, where additional gateways and start events are added.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-15&engl=1}
}
@inproceedings {INPROC-2011-14,
   author = {Oliver Kopp and Frank Leymann and Tobias Unger and Sebastian Wagner},
   title = {{Towards The Essential Flow Model}},
   booktitle = {Proceedings of the 3rd Central-European Workshop on Services and their Composition (ZEUS 2011)},
   editor = {Daniel Eichhorn and Agnes Koschmider and Huayu Zhang},
   publisher = {CEUR-WS.org},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {CEUR Workshop Proceedings},
   volume = {705},
   pages = {26--33},
   type = {Workshop Paper},
   month = {March},
   year = {2011},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://zeus2011.aifb.kit.edu/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Many of today's manufacturing projects are so complex that they cannot be conducted only by one company anymore. Current approaches for modeling inter-enterprise processes require an early decision on the way activities are connected. The modeler has to decide between control flow and message flow. This implies an early decision on the used IT-technology. We present a modeling approach where this decision is postponed to a later modeling phase. This enables modelers to concentrate on the essentials of the model.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-14&engl=1}
}
@inproceedings {INPROC-2011-13,
   author = {David Schumm and Gregor Latuske and Frank Leymann and Ralph Mietzner and Thorsten Scheibler},
   title = {{State Propagation for Business Process Monitoring on Different Levels of Abstraction}},
   booktitle = {Proceedings of the 19th European Conference on Information Systems (ECIS 2011)},
   address = {Helsinki, Finland},
   publisher = {-},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--12},
   type = {Conference Paper},
   month = {June},
   year = {2011},
   keywords = {Process Monitoring, Process View, State Abstraction},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     D.2.2 Software Engineering Design Tools and Techniques,     H.4.1 Office Automation,     H.5.2 Information Interfaces and Presentation User Interfaces,     H.5.3 Group and Organization Interfaces},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Modeling and execution of business processes is often performed on different levels of abstraction. For example, when a business process is modeled using a high-level notation near to business such as Event-driven Process Chains (EPC), a technical refinement step is required before the process can be executed. Also, model-driven process design allows modeling a process on high-level, while executing it in a more detailed and executable low-level representation such as processes defined in the Business Process Execution Language (BPEL) or as Java code. However, current approaches for graphical monitoring of business processes are limited to scenarios in which the process that is being executed and the process that is being monitored are either one and the same or on the same level of abstraction. In this paper, we present an approach to facilitate business-oriented process monitoring while considering process design on high-level. We propose process views for business process monitoring as projections of activities and execution states in order to support business process monitoring of running process instances on different levels of abstraction. In particular, we discuss state propagation patterns which can be applied to define advanced monitoring solutions for arbitrary graph-based process languages.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-13&engl=1}
}
@inproceedings {INPROC-2011-12,
   author = {Mirko Sonntag and Dimka Karastoyanova},
   title = {{Concurrent Workflow Evolution}},
   booktitle = {Electronic Communications of the EASST, Volume 37, ISSN 1863-2122},
   publisher = {Gesellschaft f{\"u}r Informatik e.V. (GI)},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--12},
   type = {Workshop Paper},
   month = {March},
   year = {2011},
   issn = {1863-2122},
   keywords = {Workflow evolution; scientific workflows; Model-as-you-go; BPEL},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   contact = {Mirko.Sonntag@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Workflow evolution is a collective term for concepts that deal with changes of workflow models. Adapted workflow models are deployed on a workflow engine as new model version. That means two versions of the same model are deployed on the engine. Typically, this results in conflicts between the workflow models. For example, how does a client find and choose the desired workflow version to instantiate? Typically, these problems are solved by deactivating the old model. New instances can only be created for the new model. In our work on scientific workflows we recognized that there are cases where it is desired to keep the old model activated. In this paper we investigate what it means to have several model versions active. We develop a general concept for this “concurrent workflow evolution” that solves emerging problems. Moreover, we show how this concept can be realized with BPEL.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-12&engl=1}
}
@inproceedings {INPROC-2011-07,
   author = {Peter Reimann and Michael Reiter and Holger Schwarz and Dimka Karastoyanova and Frank Leymann},
   title = {{SIMPL - A Framework for Accessing External Data in Simulation Workflows}},
   booktitle = {Datenbanksysteme f{\"u}r Business, Technologie und Web (BTW 2011), 14. Fachtagung des GI-Fachbereichs „Datenbanken und Informationssysteme“ (DBIS), Proceedings, 02.-04. M{\"a}rz 2011, Kaiserslautern, Germany},
   editor = {Gesellschaft f{\"u}r Informatik (GI)},
   publisher = {Lecture Notes in Informatics (LNI)},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Series of the Gesellschaft f{\"u}r Informatik (GI)},
   volume = {180},
   pages = {534--553},
   type = {Conference Paper},
   month = {March},
   year = {2011},
   isbn = {978-3-88579-274-1},
   keywords = {Data Provisioning; Workflow; Scientific Workflow; Simulation Workflow; BPEL; WS-BPEL; SIMPL},
   language = {English},
   cr-category = {H.2.8 Database Applications,     H.4.1 Office Automation},
   contact = {Peter Reimann Peter.Reimann@ipvs.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Adequate data management and data provisioning are among the most important topics to cope with the information explosion intrinsically associated with simulation applications. Today, data exchange with and between simulation applications is mainly accomplished in a file-style manner. These files show proprietary formats and have to be transformed according to the specific needs of simulation applications. Lots of effort has to be spent to find appropriate data sources and to specify and implement data transformations. In this paper, we present SIMPL – an extensible framework that provides a generic and consolidated abstraction for data management and data provisioning in simulation workflows. We introduce extensions to workflow languages and show how they are used to model the data provisioning for simulation workflows based on data management patterns. Furthermore, we show how the framework supports a uniform access to arbitrary external data in such workflows. This removes the burden from engineers and scientists to specify low-level details of data management for their simulation applications and thus boosts their productivity.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-07&engl=1}
}
@inproceedings {INPROC-2011-05,
   author = {Monika Weidmann and Falko K{\"o}tter and Maximilien Kintz and Daniel Schleicher and Ralph Mietzner and Frank Leymann},
   title = {{Adaptive Business Process Modeling in the Internet of Services (ABIS)}},
   booktitle = {Adaptive Business Process Modeling in the Internet of Services (ABIS)},
   editor = {Proceedings of the Sixth International Conference on Internet and Web Applications and Services (ICIW) 2011},
   publisher = {Xpert Publishing Services},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {29--34},
   type = {Conference Paper},
   month = {March},
   year = {2011},
   keywords = {Adaptive; business process; modelling},
   language = {German},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In the Internet of Services many companies work together in interorganizational business processes. For the resulting ad-hoc business interaction it is necessary to align business processes of the business partners, especially in communcation processes. These business processes can be partly standardized, but need to be slightly adapted for several similar use cases by the involved companies. This fosters adaptability and reuse for the business partners.We present an approach for adaptive business process modeling in the Internet of Services (ABIS) which allows creation of adaptable process templates. These templates are then used to create variants of processes allowing companies to work together in an interorganizational setting.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-05&engl=1}
}
@inproceedings {INPROC-2011-04,
   author = {Oliver Kopp and Lasse Engler and Tammo van Lessen and Frank Leymann and J{\"o}rg Nitzsche},
   title = {{Interaction Choreography Models in BPEL: Choreographies on the Enterprise Service Bus}},
   booktitle = {Subject-Orientation as Enabler for the Next Generation of BPM Tools and Methods - Second International Conference S-BPM ONE 2010},
   editor = {A. Fleischmann and W. Schmidt and D. Seese and R. Singer},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Communications in Computer and Information Science},
   volume = {138},
   pages = {36--53},
   type = {Conference Paper},
   month = {January},
   year = {2011},
   doi = {10.1007/978-3-642-23135-3_3},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://www.aifb.kit.edu/web/S-bpm-one/2010/en},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Interactions between services may be globally captured by choreographies. We introduce BPELgold supporting modeling interaction choreography models using BPEL. We show the usage of BPELgold in an enterprise service bus to ensure an executed message exchange complies with a pre-defined choreography.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2011-04&engl=1}
}
@inproceedings {INPROC-2010-99,
   author = {Hanna Eberle and Frank Leymann and Daniel Schleicher and David Schumm and Tobias Unger},
   title = {{Process Fragment Composition Operations}},
   booktitle = {Proceedings of APSCC 2010},
   publisher = {IEEE Xplore},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {157--163},
   type = {Conference Paper},
   month = {December},
   year = {2010},
   doi = {10.1109/APSCC.2010.72},
   isbn = {978-0-7695-4305-5},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The construction kit principle is a well-known software engineering paradigm to foster reusability. In case the construction kit principle is applied at runtime it is even a way to implement flexibility. In today’s workflow technology the construction kit principle is applied, e.g. in in hierarchical modeling approaches using subprocesses. In this paper we propose a construction kit application based on process fragment. In contrast to subprocesses, process fragments represent non-complete process knowledge, which needs to be integrated with further process knowledge to become a complete process model. Integrating one process fragment with another process fragment requires complex composition operations, since process fragments do not represent the implementation of a single abstract activity like in subprocesses, but are knitted together on the same level of granularity. The advantage of process fragments lies in their means to represent noncomplete process knowledge. In this paper we propose a formal process fragment modeling language, which is based on current workflow standard languages, like BPMN. Based on this modeling language we design a basic operation set, which allows to compose process fragments.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-99&engl=1}
}
@inproceedings {INPROC-2010-98,
   author = {Hanna Eberle and Frank Leymann and Tobias Unger},
   title = {{Implementation Architectures for Adaptive Workflow Management}},
   booktitle = {ADAPTIVE 2010},
   publisher = {Xpert Publishing Services},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--6},
   type = {Conference Paper},
   month = {November},
   year = {2010},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Business processes are often required to be highly flexible and adaptive due to the fact, that business conditions change. Therefore, there exist a lot adaptation and flexibility concepts for workflows. However, workflow adaptation concepts are often discussed on the language level neglecting a discussion on the implementation architectures. Until now, effective implementation architectures have not been investigated. Therefore, the main contribution of this work is to research three implementation strategies for adaptive workflow management, which we discuss with respect to modeling requirements and change management.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-98&engl=1}
}
@inproceedings {INPROC-2010-96,
   author = {Immanuel Trummer and Frank Leymann and Ralph Mietzner and Walter Binder},
   title = {{Cost-Optimal Outsourcing of Applications into the Clouds}},
   booktitle = {Proceedings of the 2nd International Conference on Cloud Computing 2010 (CloudCom 2010) (to appear)},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {December},
   year = {2010},
   keywords = {Cloud computing; Minimizing application running costs; Selecting optimal providers; Constraint programming},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   contact = {Ralph Mietzner},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Commercial services for provisioning software components and virtual infrastructure in the cloud are emerging. For customers, this creates a multitude of possibilities for outsourcing part of the IT-stack to third parties in order to run their applications. These possibilities are associated with different running costs, so cloud customers have to determine the optimal solution. In this paper, we present and experimentally evaluate an algorithm that solves the corresponding optimization problem. We assume that applications are described as templates, fixing the deployment structure and constraining the properties of the used soft- and hardware components. Different parts of the application may be outsourced to different providers and several levels of outsourcing can be considered. However, dependencies between different parts of the application have to be respected. Our algorithm decomposes the application graph in a first step in order to discover all suitable cloud provisioning services from a registry. It determines the optimal solution by representing the problem as constraint optimization problem that can be solved by an existing solver implementation.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-96&engl=1}
}
@inproceedings {INPROC-2010-95,
   author = {Ralph Mietzner and Christoph Fehling and Dimka Karastoyanova and Frank Leymann},
   title = {{Combining Horizontal and Vertical Composition of Services}},
   booktitle = {Proceedings of IEEE International Conference on Service-Oriented Computing and Applications (SOCA 2010)},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {December},
   year = {2010},
   keywords = {service composition; vertical composition; cloud; provisioning; virtual service},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   contact = {Ralph Mietzner},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Service composition is a well-established field of research in the service community. Services are commonly regarded as black boxes with well-defined interfaces that can be recursively aggregated into new services. The black-box nature of services does not only include the service implementation but also the middleware and hardware to run the services. Thus, service composition techniques are typically limited to choosing between a set of available services. In this paper we keep the black-box nature and the principle of information hiding for the service implementation, but break up services vertically. By introducing vertical service composition, we allow services to be provisioned on the right middleware when they are requested, thus making service-binding more powerful as services with the desired quality of service can be provisioned on demand. We introduce the concept of vertical service composition and present an extension to an enterprise service bus that implements the concept of vertical service composition by combining concepts from provisioning with those of (dynamic) service binding.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-95&engl=1}
}
@inproceedings {INPROC-2010-94,
   author = {Ralph Mietzner and Frank Leymann},
   title = {{A Self-Service Portal for Service-Based Applications}},
   booktitle = {Proceedings of IEEE International Conference on Service-Oriented Computing and Applications (SOCA 2010) (to appear)},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {December},
   year = {2010},
   keywords = {Cloud; Self-Service Portal; Provisioning; Composite Applications},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   contact = {Ralph Mietzner},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Enterprises today constantly seek to reduce the cost of their IT-operations. One popular approach is to outsource (parts) of these IT-operations. With the advent of Cloud computing, the outsourcing of infrastructure, runtime platforms and even whole applications has been greatly facilitated. With platforms such as Amazon’s EC2 or Salesforce’s Force.com customers can select from a set of pre-defined machine images or applications that they can then run on-demand. However, all these platforms employ proprietary technology that does not permit to model, offer, configure and automatically deploy applications in the cloud in a generic manner. In this paper we introduce metamodels, algorithms and tools for application vendors to describe composite service-based cloud applications independently of the provider that later offers them. We describe how customers can customize such service-based applications and how providers can automatically provision the individual services required by the application, thus offering customized applications to their customers while minimizing costs by sharing services and infrastructure across customers. We report on the architecture and implementation of our prototype and show sample applications.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-94&engl=1}
}
@inproceedings {INPROC-2010-93,
   author = {Daniel Schleicher and Monika Weidmann and Frank Leymann and David Schumm},
   title = {{Compliance Scopes: Extending the BPMN 2.0 Meta Model to Specify Compliance Requirements}},
   booktitle = {Proceedings of SOCA 2010},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {December},
   year = {2010},
   keywords = {BPMN; Compliance; Workflow Management},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Compliance of business processes is becoming increasingly important in the domain of business process design. Despite that, human process designers must be able to concentrate on the business goals which a business process needs to fulfil. Compliance aspects of the business process should not be in the main focus of the human process designer during the development phase. Therefore, tools must support human process designers in developing compliant business processes. In this paper we introduce the concept of compliance scopes. Compliance scopes are areas in a business process where certain compliance conditions must hold. These conditions are attached to the compliance scopes. Compliance scopes can be applied to existing business process models as well as to process templates. In this way compliance rules are applied to certain areas of a business process. During design time, compliance scopes can be used in graphical workbenches to evaluate modifications to business processes.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-93&engl=1}
}
@inproceedings {INPROC-2010-92,
   author = {Aliaksandr Birukou and Vincenzo D'Andrea and Frank Leymann and Jacek Serafinski and Patr{\'\i}cia Silveira and Steve Strauch and Marek Tluczek},
   title = {{An Integrated Solution for Runtime Compliance Governance in SOA}},
   booktitle = {Proceedings of the 8th International Conference on Service-Oriented Computing (ICSOC'10), San Francisco, California, USA, December 7-10, 2010},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {122--136},
   type = {Conference Paper},
   month = {December},
   year = {2010},
   doi = {10.1007/978-3-642-17358-5_9},
   keywords = {Compliance Governance, Business Process, Monitoring, SOA, Complex Event Processing},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   contact = {Please send an e-mail to steve.strauch@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In response to recent nancial scandals (e.g. those involving Enron, Fortis, Parmalat), new regulations for protecting the society from nancial and operational risks of the companies have been introduced. Therefore, companies are required to assure compliance of their operations with those new regulations as well as those already in place. Regulations are only one example of compliance sources modern organizations deal with every day. Other sources of compliance include licenses of business partners and other contracts, internal policies, and international standards. The diversity of compliance sources introduces the problem of compliance governance in an organization. In this paper, we propose an integrated solution for runtime compliance governance in Service-Oriented Architectures (SOAs). We show how the proposed solution supports the whole cycle of compliance management: from modeling compliance requirements in domain-speci c languages through monitoring them during process execution to displaying information about the current state of compliance in dashboards. We focus on the runtime part of the proposed solution and describe it in detail.We apply the developed framework in a real case study coming from EU FP7 project COMPAS, and this case study is used through the paper to illustrate our solution.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-92&engl=1}
}
@inproceedings {INPROC-2010-85,
   author = {Mirko Sonntag and Dimka Karastoyanova},
   title = {{BPEL’n’Aspects And Compensation: Adapted Service Orchestration Logic and its Compensation Using Aspects}},
   booktitle = {Proceedings of the 8th Int. Conf. on Service-Oriented Computing (ICSOC 2010), Demo Track, 2010},
   editor = {Mathias Weske and Jian Yang and Paul Maglio and Marcelo Fantinato},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--2},
   type = {Workshop Paper},
   month = {December},
   year = {2010},
   keywords = {Service orchestration; BPEL; compensation; aspect-orientation; adaptability},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   contact = {sonntag@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {One of the main weaknesses of workflow management systems is their inflexibility regarding process changes. To address this drawback in our work on the BPEL’n’Aspects approach we developed a standards-based mechanism to adapt the control flow of BPEL processes [1]. It uses AOP techniques to non-intrusively weave Web service invocations in terms of aspects into BPEL processes. Aspects can be inserted before, instead or after BPEL elements and that way adaptation of running processes is enabled. In this work we want to present a novel extension of the BPEL’n’Aspects prototype that deals with the compensation of weaved-in aspects in a straight-forward manner. The extension enormously improves the applicability of the approach in real-world scenarios: processes in production need the means to compensate behavior that was inserted into the process in the course of adaptation steps. The ability to compensate weaved-in aspects distinguishes our approach from other existing concepts that introduce AOP techniques to business processes.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-85&engl=1}
}
@inproceedings {INPROC-2010-84,
   author = {Mirko Sonntag and Dimka Karastoyanova and Ewa Deelman},
   title = {{BPEL4Pegasus: Combining Business and Scientific Workflows}},
   booktitle = {Proceedings of the 8th Int. Conf. on Service-Oriented Computing (ICSOC 2010), Demo Track, 2010},
   editor = {Mathias Weske and Jian Yang and Paul Maglio and Marcelo Fantinato},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--2},
   type = {Workshop Paper},
   month = {December},
   year = {2010},
   keywords = {Scientific workflows; business workflows; human tasks; Pegasus; BPEL},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   contact = {sonntag@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Business and scientific workflow management systems (WfMS) offer different features to their users because they are developed for different application areas with different requirements. Research is currently being done to extend business WfMSs by functionality that meets requirements of scientists and scientific applications. The idea is to bring the strengths of business WfMSs to e-Science. This means great effort in re-implementing features already offered by scientific WfMSs. In our work, we investigated another approach, namely combining business and scientific workflows and thus harnessing the advantages of both. We demonstrate a prototype that implements this idea with BPEL as business workflow language and Pegasus as scientific WfMS. Our motivation is the fact that the manual work to correctly install and configure Pegasus can be supervised by a BPEL workflow to minimize sources of failures and automate the overall process of scientific experimenting.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-84&engl=1}
}
@inproceedings {INPROC-2010-77,
   author = {Philipp Leitner and Branimir Wetzstein and Dimka Karastoyanova and Waldemar Hummer and Schahram Dustdar and Frank Leymann},
   title = {{Preventing SLA Violations in Service Compositions Using Aspect-Based Fragment Substitution}},
   booktitle = {Proceedings of the 8th International Conference on Service Oriented Computing (ICSOC 2010)},
   publisher = {Springer Berlin Heidelberg},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {December},
   year = {2010},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In this paper we show how the application of the aspect-oriented programming paradigm to runtime adaptation of service compositions can be used to prevent SLA violations. Adaptations are triggered by predicted violations, and are implemented as substitutions of fragments in the service composition. Fragments are full-fledged standalone compositions, and are linked into the original composition via special activities, which we refer to as virtual activities. Before substitution we evaluate fragments with respect to their expected impact on the performance of the composition, and choose those fragments which are best suited to prevent a predicted violation. We show how our approach can be implemented using Windows Workflow Foundation technology, and discuss our work based on an illustrative case study.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-77&engl=1}
}
@inproceedings {INPROC-2010-76,
   author = {Daniel Schleicher and Tobias Anstett and Frank Leymann and David Schumm},
   title = {{Compliant Business Process Design Using Refinement Layers}},
   booktitle = {OTM 2010 Conferences},
   editor = {T. Dillon et al. R. Meersman},
   publisher = {Springer Verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {October},
   year = {2010},
   keywords = {Compliance, Refinement, BPEL, business process},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In recent years compliance has emerged as one of the big IT challenges enterprises are faced with. The management of a multitude of regulations and the complexity of current business processes are problems that need to be addressed. In this paper we present an approach based on so-called compliance templates to develop and manage compliant business processes involving different stakeholders. We introduce the concept of a refinement process. In the refinement process each compliance template is refined in a layered way to get an executable business process. The refinement steps are executed on refinement layers by different stakeholders. Compliance constraints are used to restrict the way a compliance template can be refined. Introduced in a certain refinement layer of the refinement process, compliance constraints are propagated to higher refinement layers.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-76&engl=1}
}
@inproceedings {INPROC-2010-75,
   author = {David Schumm and Tobias Anstett and Frank Leymann and Daniel Schleicher and Steve Strauch},
   title = {{Essential Aspects of Compliance Management with Focus on Business Process Automation}},
   booktitle = {INFORMATIK 2010: Business Process and Service Science Proceedings of ISSS and BPSC},
   editor = {Witold Abramowicz and Rainer Alt and Klaus-Peter F{\"a}hnrich and Bogdan Franczyk and Leszek A. Maciaszek},
   publisher = {Gesellschaft f{\"u}r Informatik e.V. (GI)},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Informatics},
   volume = {177},
   pages = {127--138},
   type = {Conference Paper},
   month = {September},
   year = {2010},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Compliance requirements coming from laws, regulations and internal policies constrain how a company may carry out its business. A company must take various different actions for preventing compliance violations and for detecting them. Business processes have to be changed accordingly in order to adhere to these requirements. Manual controls need to be installed in order to affect the work which is done outside of IT systems. Technical controls are required for assuring compliance within IT systems. In this paper, we present a compliance management model that captures the compliance problem from a holistic point of view. We elaborate on a technical control which is called compliance fragment and we position it in the compliance management model. A compliance fragment is a connected, possibly incomplete process graph that can be used as a reusable building block for ensuring a consistent specification and integration of compliance into a workflow. In particular, we propose language extensions to BPEL for representing compliance fragments. Furthermore, we introduce a methodology for integrating compliance fragments into given workflows.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-75&engl=1}
}
@inproceedings {INPROC-2010-74,
   author = {Oliver Kopp and Frank Leymann and Daniel Wutke},
   title = {{Fault Handling in the Web Service Stack}},
   booktitle = {Service-Oriented Computing - ICSOC 2010},
   publisher = {Springer Berlin Heidelberg},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science},
   volume = {6470},
   pages = {303--317},
   type = {Conference Paper},
   month = {December},
   year = {2010},
   doi = {10.1007/978-3-642-17358-5_21},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://icsoc10.disi.unitn.it/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The Web services platform architecture consists of different layers for exchanging messages. There can be faults happening at each layer during the message exchange. This paper first presents the fault handling strategies of current standards and provides insight on the concepts behind them. Second, current service middleware is reviewed whether and how it follows the fault handling strategies.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-74&engl=1}
}
@inproceedings {INPROC-2010-73,
   author = {Oliver Kopp and Hanna Eberle and Frank Leymann and Tobias Unger},
   title = {{The Subprocess Spectrum}},
   booktitle = {Proceedings of the Business Process and Services Computing Conference: BPSC 2010},
   publisher = {Gesellschaft f{\"u}r Informatik e.V. (GI)},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Informatics},
   volume = {P-177},
   pages = {267--279},
   type = {Conference Paper},
   month = {September},
   year = {2010},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://www.bpsc-conf.org/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Using hierarchical structurings in process design is a frequent process modeling technique. Subprocesses are a common way to enable hierarchical structuring. Current approaches have a tight view on the syntactical restrictions of subprocesses and do not investigate different autonomy properties in detail. This paper fills this gap and broadens the current subprocess definition to a spectrum of possibilities of subprocess notations. Thereby, three classifications are introduced: subprocess autonomy, interaction between parent process and subprocess, and execution of subprocesses.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-73&engl=1}
}
@inproceedings {INPROC-2010-72,
   author = {Tobias Unger and Dieter Roller},
   title = {{Applying Processes for User-driven Refinement of People Activities}},
   booktitle = {Proceedings of the 14th IEEE International EDOC Conference (EDOC 2010)},
   publisher = {IEEE Computer Society Press},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {October},
   year = {2010},
   doi = {10.1109/edocw.2010.34},
   language = {English},
   cr-category = {D.3.3 Programming Language Constructs and Features,     H.4.1 Office Automation,     H.5.2 Information Interfaces and Presentation User Interfaces},
   contact = {unger@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Many workflows contain activities that are carried out by business professionals using a set of task specific tools. These activities, usually called people activities, are usually modeled as a single task within an overall process model; the actual processing by the business professional however involves in general many different steps that each business professional carries out according to their personal preferences. We introduce in this paper the architecture of a system that helps business professionals organizing people activities. The system provides for the dynamic definition and management of sub tasks, the organization and management of sub tasks as parts of a user-specific process models and the interaction with the workflow management system that controls the process instances containing those people activities. The main contribution of this work is a concept allowing user to refine people activities using personal activity processes which are modeled by users themselves.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-72&engl=1}
}
@inproceedings {INPROC-2010-67,
   author = {Gabriela Gheorghe and Bruno Crispo and Daniel Schleicher and Tobias Anstett and Frank Leymann and Ralph Mietzner and Ganna Monakova},
   title = {{Combining Enforcement Strategies in Service Oriented Architectures}},
   booktitle = {accepted for publication in ICSOC 2010 proceedings},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {288--302},
   type = {Conference Paper},
   month = {December},
   year = {2010},
   keywords = {Enforcement, ESB, BPEL},
   language = {German},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Business regulations on enterprise applications cover both infrastructure and orchestration levels of the SOA environment. Enforcing such requirements can be awkward or impossible to emulate at one level within the other. Based on previous work, we make a comparison between enforcement capabilities at business and infrastructure level. Our contribution is to make a first step towards a policy enforcement model that combines the strengths of the processlevel enforcement mechanisms with those of the message bus. The advantage of such a model is not only that infrastructure and process-level requirements are enforced by the correct mechanisms, but also that enforcement at both levels can be combined simultaneously. We present the architecture and a first prototype of such a model to show its feasibility.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-67&engl=1}
}
@inproceedings {INPROC-2010-55,
   author = {Frank Leymann},
   title = {{BPEL vs. BPMN 2.0: Should You Care?}},
   booktitle = {2nd International Workshop on BPMN},
   publisher = {Springer Verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Business Information Processing},
   type = {Workshop Paper},
   month = {October},
   year = {2010},
   keywords = {Workflow management systems; process engines; process modeling; metamodels; standards; BPEL; BPMN},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://www.bpmn2010.org/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {BPMN 2.0 is an executable process modeling language. Thus, its relation to BPEL becomes an issue. In this paper, we propose a positioning of both languages, introduce the notion of a “native metamodel”, and emphasize the role of the native metamodel of a process engine for the actual discussion.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-55&engl=1}
}
@inproceedings {INPROC-2010-52,
   author = {David Schumm and Dimka Karastoyanova and Frank Leymann and Steve Strauch},
   title = {{Fragmento: Advanced Process Fragment Library}},
   booktitle = {Proceedings of the 19th International Conference on Information Systems Development (ISD'10), Prague, Czech Republic, August 25 - 27, 2010},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {659--670},
   type = {Conference Paper},
   month = {August},
   year = {2010},
   isbn = {978-1-4419-9645-9},
   keywords = {Process Fragment; Process Design; Reusability; Process Library},
   language = {English},
   cr-category = {H.4.1 Office Automation,     D.3.3 Programming Language Constructs and Features},
   contact = {David.Schumm@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Reuse is a common discipline for decreasing software development time and for improving overall quality, independent from the domain. As business processes represent a fundamental asset of an organization, several concepts for enabling reuse during process modeling have been proposed. However, only few concrete examples for reusable process artifacts have been discussed so far. In this paper, we present the concept of process fragments and an example collection of process fragments for illustrating our reuse concept and for showing that it can ac-tually be applied in practice for an easier and faster development of process-based applications. The fragment examples demonstrate different characteristics such fragments may exhibit. We also argue that this work will encourage reuse of process logic in terms of fragments since it also provides an opportunity to design and develop a process fragment library for collecting process logic explicitly. As technical enabler for the approach we present a prototype called Fragmento.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-52&engl=1}
}
@inproceedings {INPROC-2010-51,
   author = {David Schumm and Tobias Anstett and Frank Leymann and Daniel Schleicher},
   title = {{Applicability of Process Viewing Patterns in Business Process Management}},
   booktitle = {Proceedings of the International Workshop on Models and Model-driven Methods for Service Engineering (3M4SE 2010), in conjunction with the 14th IEEE International EDOC Conference (EDOC 2010)},
   address = {Los Alamitos},
   publisher = {IEEE Computer Society Press},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {79--88},
   type = {Workshop Paper},
   month = {October},
   year = {2010},
   keywords = {Process Analysis, Process View, Model Transformation, Business Process Management},
   language = {English},
   cr-category = {D.2.2 Software Engineering Design Tools and Techniques,     H.4.1 Office Automation,     H.5.2 Information Interfaces and Presentation User Interfaces},
   contact = {David.Schumm@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Process views are an emerging concept for coping with the increasing complexity of process models. We understand a process view as the result of specific model transformations applied to a process. In this paper we discuss concrete scenarios of process view transformations for providing assistance in business process management. We show how elementary patterns of view transformations can be combined to support the design, deployment, monitoring and analysis of business processes. The process views proposed in this paper are technology independent and can be applied to any process language that can be represented by a process graph, such as the Business Process Modeling Notation (BPMN) and Event-driven Process Chains (EPC).},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-51&engl=1}
}
@inproceedings {INPROC-2010-50,
   author = {David Schumm and Frank Leymann and Alexander Streule},
   title = {{Process Viewing Patterns}},
   booktitle = {Proceedings of the 14th IEEE International EDOC Conference (EDOC 2010)},
   address = {Los Alamitos},
   publisher = {IEEE Computer Society Press},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {89--98},
   type = {Conference Paper},
   month = {October},
   year = {2010},
   keywords = {Process View, Pattern, Model Transformation, Process Analysis},
   language = {English},
   cr-category = {D.2.2 Software Engineering Design Tools and Techniques,     D.3.3 Programming Language Constructs and Features,     H.4.1 Office Automation,     H.5.2 Information Interfaces and Presentation User Interfaces},
   contact = {David.Schumm@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Business processes represent a fundamental asset of a company, as they describe the core knowledge underlying its competitive advantage. Tools for modeling and analysis of business processes have to cope with the increasing complexity of these processes. A view on a process intends to abstract from details and make complex processes easier to understand. A process view results from specific transformations applied to a process model. In this paper we introduce a metamodel for process views as well as process viewing patterns, which specify elementary transformations to alter an existing process. The patterns are presented in a technology independent manner and can be applied to any process language that can be represented by a process graph.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-50&engl=1}
}
@inproceedings {INPROC-2010-49,
   author = {David Schumm and Frank Leymann and Alexander Streule},
   title = {{Process Views to Support Compliance Management in Business Processes}},
   booktitle = {Proceedings of the 11th International Conference on Electronic Commerce and Web Technologies (EC-Web 2010)},
   editor = {Francesco Buccafurri and Giovanni Semeraro},
   address = {Bilbao, Spain},
   publisher = {Springer-Verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Business Information Processing},
   volume = {61},
   pages = {131--142},
   type = {Conference Paper},
   month = {September},
   year = {2010},
   keywords = {Process View, Model Transformation, Compliance},
   language = {English},
   cr-category = {D.2.2 Software Engineering Design Tools and Techniques,     H.4.1 Office Automation,     H.5.2 Information Interfaces and Presentation User Interfaces},
   contact = {David.Schumm@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Compliance has become an important driver in business process management, as it requires profound and traceable changes of the processes. Besides the increasing demand for security, privacy and trust, compliance also needs consistent integration and management of process structures related to compliance. We use the notion of compliance fragments to refer to such structures. In this paper we discuss the challenges of managing compliance fragments in business processes. Extraction, integration, highlighting and hiding of compliance fragments are the challenges we refer to. For extraction and hiding of compliance fragments we present an implementation for the process execution language BPEL, based on process view transformation concepts.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-49&engl=1}
}
@inproceedings {INPROC-2010-48,
   author = {Sema Zor and Katharina G{\"o}rlach and Frank Leymann},
   title = {{Using BPMN for Modeling Manufacturing Processes}},
   booktitle = {Sustainable Production and Logistics in Global Networks - Proceedings of 43rd CIRP International Conference on Manufacturing Systems},
   editor = {Wilfried Sihn and Peter Kuhlang},
   address = {Wien, Graz},
   publisher = {Neuer Wissenschaftlicher Verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {515--522},
   type = {Conference Paper},
   month = {May},
   year = {2010},
   isbn = {978-3-7083-0686-5},
   keywords = {BPMN; Manufacturing},
   language = {English},
   cr-category = {H.4.1 Office Automation,     H.4.2 Information Systems Applications Types of Systems},
   ee = {http://icms2010.fraunhofer.at/Seiten/default.aspx},
   contact = {sema.zor@gsame.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Value Stream Mapping (VSM) is an established tech-nique to model, analyze and optimize material and information flows in a manufacturing company. VSM does supply a graphical notation, however, it does not provide an automatic execution model. As a result, the flows modeled in VSM need to be mapped to executable IT-Systems manually. This paper proposes an approach to enable automatic execution of VSM flows which is achieved by mapping the VSM language to an established business process modeling language such as the Business Process Modeling Notation (BPMN). Processes modeled in BPMN can be automatically translated into executable processes. This enables executing both, the manufacturing processes and the business processes of a company in the same IT environment. Thus, interoperability is enabled between shop floor and office area.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-48&engl=1}
}
@inproceedings {INPROC-2010-47,
   author = {Ganna Monakova and Philip Miseldine and Frank Leymann},
   title = {{An Evidence Model to Enable Constraint-Based Runtime Monitoring in SOA}},
   booktitle = {Proceedings of the The 2010 International Conference of Computer Science and Engineering: ICCSE 2010; London, UK, June 30- July 2, 2010},
   editor = {IAENG},
   address = {London},
   publisher = {IAENG},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {July},
   year = {2010},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     D.2.12 Software Engineering Interoperability},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {One of the major challenges for businesses today is to ensure that their processes are regulatory compliant. This implies that business processes must be appropriately constrained for their correct and legal operation. To evaluate such constraints, evidence of the implementation of the business process execution is needed. In a SOA, a business process is commonly realised as an orchestration of services. It is therefore necessary to observe the runtime behaviour of these services. In this paper we propose a common evidence model, which allows constraints to be modelled upon service behaviour and mapped to the available evidence. We propose an architecture to provide the runtime monitoring needed to evaluate the constraints based on this model.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-47&engl=1}
}
@inproceedings {INPROC-2010-44,
   author = {Kai H{\"a}ussermann and Christoph Hubig and Paul Levi and Frank Leymann and Oliver Simoneit and Matthias Wieland and Oliver Zweigle},
   title = {{Understanding and designing situation-aware mobile and ubiquitous computing systems - an interdisciplinary analysis on the recognition of situation with uncertain data using situation templates.}},
   booktitle = {Proceedings of International Conference on Mobile, Ubiquitous and Pervasive Computing},
   publisher = {WASET},
   institution = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   pages = {329--339},
   type = {Conference Paper},
   month = {March},
   year = {2010},
   issn = {2070-3724},
   keywords = {context-awareness; ethics; facilitation of system use through workflows},
   language = {English},
   cr-category = {H.1.0 Information Systems Models and Principles General,     H.1.1 Systems and Information Theory,     H.1.2 User/Machine Systems},
   department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Philosophie, Abteilung f{\"u}r Wissenschaftstheorie und Technikphilosophie (IP/WTTP);     University of Stuttgart, Institute of Parallel and Distributed Systems, Image Understanding;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Using spatial models as a shared common basis of information about the environment for different kinds of context- aware systems has been a heavily researched topic in the last years. Thereby the research focused on how to create, to update, and to merge spatial models so as to enable highly dynamic, consistent and coherent spatial models at large scale. In this paper however, we want to concentrate on how context-aware applications could use this information so as to adapt their behavior according to the situation they are in. The main idea is to provide the spatial model infrastructure with a situation recognition component based on generic situation templates. A situation template is - as part of a much larger situation template library - an abstract, machine- readable description of a certain basic situation type, which could be used by different applications to evaluate their situation. In this paper, different theoretical and practical issues - technical, ethical and philosophical ones - are discussed important for understanding and developing situation dependent systems based on situation templates. A basic system design is presented which allows for the reasoning with uncertain data using an improved version of a learning algorithm for the automatic adaption of situation templates. Finally, for supporting the development of adaptive applications, we present a new situation-aware adaptation concept based on workflows.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-44&engl=1}
}
@inproceedings {INPROC-2010-42,
   author = {Rania Khalaf and Frank Leymann},
   title = {{Coordination for Fragmented Loops and Scopes in a Distributed Business Process}},
   booktitle = {8th International Conference on Business Process Management (BPM 2010)},
   publisher = {Springer-Verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {September},
   year = {2010},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://www.bpm2010.org/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {This paper addresses the problem of partitioning business processes containing loops as well as compensation and fault handling scopes. The resulting process fragments can be distributed and wired together, recreating the execution semantics of the original process model. In earlier work, we presented BPEL fragmentation covering data and explicit control dependencies. We now extend the approach to handle fragmenting loops and scopes. Maintaining the focus on standards and maximizing extensibility of Web service runtimes and standards, the solution defines and uses new coordination protocols that plug into the WS-Coordination framework. An implementation is presented, extending the Active Endpoints BPEL engine and a WS-Coordination system.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-42&engl=1}
}
@inproceedings {INPROC-2010-41,
   author = {David Schumm and Oktay Turetken and Natallia Kokash and Amal Elgammal and Frank Leymann and Willem-Jan van den Heuvel},
   title = {{Business Process Compliance through Reusable Units of Compliant Processes}},
   booktitle = {Proceedings of the 1st Workshop on Engineering SOA and the Web (ESW'10)},
   editor = {Florian Daniel and Federico Michele Facca},
   address = {Vienna},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science},
   volume = {6385},
   pages = {325--337},
   type = {Workshop Paper},
   month = {October},
   year = {2010},
   keywords = {Compliance; Business Process Management; Process Fragment; Formal Modeling; Process Verification},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   contact = {David.Schumm@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Compliance management is essential for ensuring that organizational business processes and supporting information systems are in accordance with a set of prescribed requirements originating from laws, regulations, and various legislative or technical documents such as Sarbanes-Oxley Act or ISO 17799. As the violation of such requirements may lead to significant punishment for an organization, compliance management should be supported at the very early stages of business process development. In this paper, we present an integrated approach to compliance management that helps process designers to adhere to compliance requirements relevant for their processes. Firstly, we introduce a conceptual model for specifying compliance requirements originating from various compliance sources. Secondly, we propose a framework for augmenting business processes with reusable fragments to ensure process compliance to certain requirements by design. Furthermore, we discuss the formalization of compliance requirements using mathematical logics and integrate the framework for process reuse with automated software verification tools.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-41&engl=1}
}
@inproceedings {INPROC-2010-29,
   author = {Ivona Brandic and Tobias Anstett and David Schumm and Frank Leymann and Schahram Dustdar and Ralf Konrad},
   title = {{Compliant Cloud Computing (C3): Architecture and Language Support for User-driven Compliance Management in Clouds}},
   booktitle = {Proceedings of the 3rd International Conference on Cloud Computing (IEEE Cloud 2010)},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--8},
   type = {Conference Paper},
   month = {July},
   year = {2010},
   keywords = {Cloud Computing, Compliance},
   language = {English},
   cr-category = {D.3.2 Programming Language Classifications,     D.3.3 Programming Language Constructs and Features},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Cloud computing represents a promising computing paradigm, where computational power is provided similar to utilities like water, electricity or gas. While most of the Cloud providers can guarantee some measurable non-functional performance metrics e.g., service availability or throughput, there is lack of adequate mechanisms for guaranteeing certifiable and auditable security, trust, and privacy of the applications and the data they process. This lack represents an obstacle for moving most business relevant applications into the Cloud. In this paper we devise a novel approach for compliance management in Clouds, which we termed Compliant Cloud Computing (C3). On one hand, we propose novel languages for specifying compliance requirements concerning security, privacy, and trust by leveraging Domain Specific Languages and Compliance Level Agreements. On the other hand, we propose the C3 middleware responsible for the deployment of certifiable and auditable applications, for provider selection in compliance with the user requirements, and for enactment and enforcement of compliance level agreements. We underpin our approach with a use case discussing various techniques necessary for achieving security, privacy, and trust in Clouds as for example data fragmentation among different protection domains or among different geographical regions.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-29&engl=1}
}
@inproceedings {INPROC-2010-27,
   author = {Christoph Fehling and Frank Leymann and Ralph Mietzner},
   title = {{A Framework for Optimized Distribution of Tenants in Cloud Applications}},
   booktitle = {Proceedings of the 2010 IEEE International Conference on Cloud Computing (CLOUD 2010)},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--8},
   type = {Conference Paper},
   month = {July},
   year = {2010},
   keywords = {cloud, multi-tenancy, provisioning, SaaS},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Abstract—To be successful a cloud service provider has to target a preferably large customer group to leverage economies of scale. Therefore an application offered as a service in the cloud is often configurable regarding non-functional qualities, such as location or availability. Since many of these qualities depend on the resources on which the service is hosted, a large number of computing environments has to be managed by the service provider. This paper analyses the challenges arising from such a scenario and identifies several optimization opportunities originating from an intelligent distribution of users among the functionally equal resources with different quality of services. A framework enabling the development of distribution strategies exploiting these opportunities is defined. It allows modeling of resources, their deployment dependencies, and users with specific demands. An architecture and prototype of a management system is introduced to handle the required resource provisioning and user request routing. Several optimization strategies are defined and their performance is evaluated using statistical data of an existing cloud service provider.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-27&engl=1}
}
@inproceedings {INPROC-2010-26,
   author = {Mirko Sonntag and Natalia Currle-Linde and Katharina G{\"o}rlach and Dimka Karastoyanova},
   title = {{Towards Simulation Workflows With BPEL: Deriving Missing Features From GriCoL}},
   booktitle = {Proceedings of the 21st IASTED International Conference on Modelling and Simulation (MS 2010), 2010.},
   editor = {R.S. Alhajj and V.C.M. Leung and M. Saif and R. Thring},
   publisher = {ACTA Press},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {July},
   year = {2010},
   keywords = {Simulation tools and languages; Workflow management; BPEL; GriCoL},
   language = {English},
   cr-category = {H.4.1 Office Automation,     H.3.4 Information Storage and Retrieval Systems and Software},
   contact = {mirko.sonntag@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In this paper, we investigate the suitability of the generalpurpose workflow language BPEL to create executable simulation workflows. We therefore compare BPEL to GriCoL, a graphical language with proven applicability for simulation workflows in Grid environments. We discover a number of incomparable concepts in the two languages. On the one hand, BPEL’s unique features in comparison to GriCoL reveal the rationale behind the approach of using BPEL as basis for a simulation workflow language. On the other hand, based on the features of GriCoL, we are able to discuss how to extend BPEL in order to increase its expressiveness for simulation workflows.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-26&engl=1}
}
@inproceedings {INPROC-2010-23,
   author = {Mirko Sonntag and Dimka Karastoyanova},
   title = {{Next Generation Interactive Scientific Experimenting Based On The Workflow Technology}},
   booktitle = {Proceedings of the 21st IASTED International Conference on Modelling and Simulation (MS 2010), 2010.},
   editor = {R.S. Alhajj and V.C.M. Leung and M. Saif and R. Thring},
   publisher = {ACTA Press},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {July},
   year = {2010},
   keywords = {Simulation tools and languages; Workflow management; Workflow adaptation; SOA},
   language = {English},
   cr-category = {H.4.1 Office Automation,     H.3.4 Information Storage and Retrieval Systems and Software},
   contact = {mirko.sonntag@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In this paper we explore to what extent the conventional workflow technology and service-oriented architecture (SOA) principles can be applied to support scientist in their experiments. Based on the requirements imposed on systems for scientific computing, e-Science and simulations, and an extended workflow life cycle we introduce the architecture of an interactive system that reuses the conventional workflow technology. We advocate the realization of this workflow system with advanced adaptation and monitoring features because we identified that modeling of scientific applications and simulations can only be done the “scientists’ way” if the traditional workflow modeling as well as design and run time adaptation are combined in a user-friendly solution.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-23&engl=1}
}
@inproceedings {INPROC-2010-13,
   author = {Frank Leymann and Tobias Unger and Sebastian Wagner},
   title = {{On designing a people-oriented constraint-based workflow language}},
   booktitle = {Proceedings of the 2nd Central-European Workshop on Services and their Composition, ZEUS 2010, Berlin, Germany, February 25--26, 2010},
   editor = {Christian Gierds and Jan S{\"u}rmeli},
   publisher = {CEUR-WS.org},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {CEUR Workshop Proceedings},
   volume = {563},
   pages = {25--31},
   type = {Workshop Paper},
   month = {March},
   year = {2010},
   language = {German},
   cr-category = {H.4.1 Office Automation},
   ee = {http://sunsite.informatik.rwth-aachen.de/Publications/CEUR-WS/Vol-563/,     http://ceur-ws.org/Vol-563/paper3.pdf},
   contact = {unger@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The control-flow of business workflows is characterized by the strict execution order of the activities that is already defined at design time. This well-structured control-flow is for instance absolutely necessary if the workflows have to be performed fully automatically. However, this rigidity is not always appropriate for people-oriented workflows. Especially in scenarios where real world processes are only semi-structured humans should have more freedom to decide in which order they want to perform the activities. In this paper, we suggest an approach to design people-oriented workflows via constraints to make them more flexible.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-13&engl=1}
}
@inproceedings {INPROC-2010-124,
   author = {Aliaksandr Birukou and Agnieszka Betkowska Cavalcante and Fabio Casati and Soudip Roy Chowdhury and Vincenzo D'Andrea and Frank Leymann and Ernst Oberortner and Jacek Serafinski and Patricia Silveira and Steve Strauch and Marek Tluczek},
   title = {{An Integrated Solution for Runtime Compliance Governance in SOA}},
   booktitle = {Proceedings of the 8th International Conference on Service-Oriented Computing (ICSOC'10)},
   editor = {Paul P Maglio and Mathias Weske and Jian Yang and Marcelo Fantinato},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Demonstration},
   month = {December},
   year = {2010},
   keywords = {compliance governance; DSL, monitoring, SOA, CEP},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   contact = {steve.strauch@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Compliance governance in organizations has been recently gaining importance because of new regulations and the diversity of compliance sources. In this demo we will show an integrated solution for runtime compliance governance in Service-Oriented Architectures (SOAs). The proposed solution supports the whole cycle of compliance management and has been tested in a real world case study.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-124&engl=1}
}
@inproceedings {INPROC-2010-12,
   author = {Tobias Unger and Hanna Eberle and Frank Leymann},
   title = {{Research challenges on person-centric flows}},
   booktitle = {Proceedings of the 2nd Central-European Workshop on Services and their Composition, ZEUS 2010, Berlin, Germany, February 25--26, 2010},
   editor = {Christian Gierds and Jan S{\"u}rmeli},
   publisher = {CEUR-WS.org},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {CEUR Workshop Proceedings},
   volume = {563},
   pages = {97--104},
   type = {Workshop Paper},
   month = {March},
   year = {2010},
   language = {German},
   cr-category = {H.4.1 Office Automation},
   ee = {http://sunsite.informatik.rwth-aachen.de/Publications/CEUR-WS/Vol-563/,     http://ceur-ws.org/Vol-563/paper12.pdf},
   contact = {unger@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Research in the domain of Workflow Management focuses increasingly on service orchestrations. Often the fact is neglected that a huge part of the activities of business processes are performed by people. Especially, in the domain of pervasive computing processes are describing sequences of real world activities which are invariably performed by people. Therefore we consider the role of people participating in workflows from a new perspective. The basic idea of this work is to transfer the workflow metaphor to people processing their tasks. Therefore, we introduce the concept of a person-centric flow, which denotes such an implicit flow scheduled and executed by a single person. Secondly, we provide a list on research challenges on person-centric flows.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-12&engl=1}
}
@inproceedings {INPROC-2010-115,
   author = {Mirko Sonntag and Dimka Karastoyanova and Ewa Deelman},
   title = {{Bridging The Gap Between Business And Scientific Workflows}},
   booktitle = {Proceedings of the IEEE 6th International Conference on e-Science, Brisbane, Australia, December 7-10, 2010},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {206--213},
   type = {Conference Paper},
   month = {December},
   year = {2010},
   doi = {10.1109/eScience.2010.12},
   keywords = {Scientific workflows; Business workflows; Human tasks; Pegasus; BPEL},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   contact = {sonntag@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Due to their different target applications business and scientific workflow systems provide different sets of features to their users. Significant amount of research is currently being done to employ the business workflow technology in the scientific domain. This usually means extending the workflow language and thus the modeling tool and execution engine. In this paper we aim to bring business and scientific workflows together in order to exploit the advantages of both. We explore the interplay between business and scientific workflows in the context of human interactions with the management of workflow execution. We present an approach and implementation based on BPEL and Pegasus and show that the approach can be beneficial to scientists.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-115&engl=1}
}
@inproceedings {INPROC-2010-114,
   author = {Lukasz Juszczyk and Daniel Schall and Ralph Mietzner and Schahram Dustdar and Frank Leymann},
   title = {{CAGE: Customizable Large-scale SOA Testbeds in the Cloud}},
   booktitle = {Proceedings of the 6th INternational Workshop on Engineering Service Oriented Applications - WESOA 10 (to appear)},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--1},
   type = {Workshop Paper},
   month = {December},
   year = {2010},
   keywords = {Soa, composite applications, testing, cloud, customization},
   language = {English},
   cr-category = {D.2.5 Software Engineering Testing and Debugging},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Large-scale and complex distributed systems are increasingly implemented as SOAs. These comprise diverse types of components, e.g., Web services, registries, workflow engines, and services buses, that interact with each others to establish composite functionality. The drawback of this trend is that testing of complex SOAs becomes a challenging task. During the development phase, testers must verify the system's correct functionality, but often do not have access to adequate testbeds. In this paper, we present an approach for solving this issue. We combine the Genesis2 testbed generator, that emulates SOA environments, with Cafe, a framework for provisioning of component-based applications in the cloud. Our approach allows to model large-scale service-based testbed infrastructures, to specify their behavior, and to deploy these automatically in the cloud. As a result, testers can emulate required environments on-demand for evaluating SOAs at runtime.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-114&engl=1}
}
@inproceedings {INPROC-2010-11,
   author = {Oliver Kopp and Frank Leymann and Fei Wu},
   title = {{Mapping interconnection choreography models to interaction choreography models}},
   booktitle = {Proceedings of the 2nd Central-European Workshop on Services and their Composition, ZEUS 2010},
   address = {online},
   publisher = {CEUR-WS.org},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {CEUR Workshop Proceedings},
   volume = {563},
   pages = {81--88},
   type = {Workshop Paper},
   month = {March},
   year = {2010},
   isbn = {1613-0073},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2010-11/INPROC-2010-11.pdf,     http://www2.informatik.hu-berlin.de/top/zeus/,     http://sunsite.informatik.rwth-aachen.de/Publications/CEUR-WS/Vol-563/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Choreographies offer a global view on interacting processes. There are two ways to capture this global view: interaction models and interconnection models. Although there is a mapping from interaction models to interconnection models, there is no mapping vice versa. This paper fills this gap and provides a first approach mapping interconnection models to interaction models: The presented approach transforms BPMN models into iBPMN models by using Petri nets as intermediate format.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-11&engl=1}
}
@inproceedings {INPROC-2010-105,
   author = {Matthias Wieland and Frank Leymann and Michael Sch{\"a}fer and Dominik Lucke and Carmen Constantinescu and Engelbert Westk{\"a}mper},
   title = {{Using Context-aware Workflows for Failure Management in a Smart Factory}},
   booktitle = {Proceedings of the Fourth International Conference on Mobile Ubiquitous Computing, Systems, Services and Technologies: UBICOMM 2010},
   address = {Florence, Italy},
   publisher = {IARIA},
   institution = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   pages = {379--384},
   type = {Conference Paper},
   month = {October},
   year = {2010},
   isbn = {978-1-61208-000-0},
   language = {English},
   cr-category = {H.1.2 User/Machine Systems,     H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems;     Universit{\"a}t Stuttgart, Institut f{\"u}r Industrielle Fertigung und Fabrikbetrieb (IFF)},
   abstract = {In factories many processes are executed in parallel. The manufacturing processes are managed by Manufacturing Execution Systems. In the case of machine failures these systems provide only rudimentary or no support to the workers or shop-floor managers. As a consequence the failures have to be fixed as fast as possible for being able to continue manufacturing processes. For such cases context-aware workflows can be used to support the workers and to coordinate the work that has to be done for repairing purposes. In the Nexus Project we introduced the concept of context-aware workflows and context integration processes to be able to implement all kinds of processes going on in a smart environment. As a case study we modeled a failure management process as a workflow and executed it in a factory. Furthermore, we show the concepts behind this kind of workflows: the context integration processes and the context-aware human tasks. Finally, end user applications for the interaction of the workers with the workflow are presented. For that we developed an application concept providing a mobile solution for workers and a web-based solution for an office environment. The main contribution of this paper is to show how to implement such a failure management process as a context-aware workflow.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-105&engl=1}
}
@inproceedings {INPROC-2010-104,
   author = {Oliver Kopp and Katharina G{\"o}rlach and Frank Leymann},
   title = {{Extending Choreography Spheres to Improve Simulations}},
   booktitle = {International Organization for Information Integration and Web-based Application and Services 2010 (iiWAS 2010)},
   publisher = {ACM},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {694--697},
   type = {Conference Paper},
   month = {November},
   year = {2010},
   doi = {10.1145/1967486.1967598},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://www.iiwas.org/conferences/iiwas2010/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In simulations scientific workflows are used to coordinate complex implementations incorporating different kinds of simulations. Typically, the amount of data to be analyzed is huge and it is impossible to store all intermediate or alternative results. Thus, the access to data services has to be coordinated such that applications read the right data and do not overwrite one another. In this paper, we present a possibility to coordinate different scientific simulations accessing and updating the same data using existing Web service technologies: We extend the concept of choreography spheres by allowing control-links between them and the property ``permeability'' stating whether a cross-boundary link may be traversed before the start or completion of a choreography sphere. This paper is the first presenting a state model for choreography spheres.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-104&engl=1}
}
@inproceedings {INPROC-2010-103,
   author = {Alexander Nowak and Frank Leymann and Ralph Mietzner},
   title = {{Towards Green Business Process Reengineering}},
   booktitle = {Proceedings of the First International Workshop on Services, Energy, \& Ecosystem: SEE2010, San Francisco, USA, December 07, 2010},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {LNCS},
   volume = {6568},
   pages = {187--192},
   type = {Workshop Paper},
   month = {December},
   year = {2010},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   contact = {alexander.nowak@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Information and communication technology has experienced a vast development and increased usage over the past few years. This development again yields to increasing energy consumption. In this paper we provide a research agenda that picks up this serious development and suggests first approaches how holistic energy efficiency could be introduced in enterprises without neglecting a company’s performance and competitiveness. We propose green Business Process Reengineering as one opportunity to make further development more sustainable with respect to the resources of our environment.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-103&engl=1}
}
@inproceedings {INPROC-2010-102,
   author = {Tobias Unger and Sebastian Wagner},
   title = {{Collaboration Aspects of Human Tasks}},
   booktitle = {Proceedings of the 1st International Workshop on Cross Enterprise Collaboration, People, and Work (CEC-PAW10)},
   address = {Hoboken, NJ},
   publisher = {-},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Workshop Paper},
   month = {September},
   year = {2010},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   contact = {unger@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Many of today's development and manufacturing projects are so complex that they cannot be conducted only by one company anymore. Such collaborations are mostly modeled and executed using business processes. Business processes are increasingly controlled automatically by IT-systems, but they still consist of many tasks that have to be performed by people. Collaborations using business process are are widely discussed in the context of choreographies and subprocesses. However, collaborations on human task level are discussed much less. The goal of this work is to lay a foundation of a cross-organizational federated task management infrastructure, which supports collaborations on task level.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-102&engl=1}
}
@inproceedings {INPROC-2010-101,
   author = {Tobias Unger and Hanna Eberle and Frank Leymann and Sebastian Wagner},
   title = {{An Event-model for Constraint-based Person-centric Flows}},
   booktitle = {Proceedings of the 2010 International Conference on Progress in Informatics and Computing (PIC-2010)},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {927--932},
   type = {Conference Paper},
   month = {December},
   year = {2010},
   isbn = {978-1-4244-6788-4},
   doi = {10.1109/PIC.2010.5687886},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://pic.sjtu.edu.cn,     http://ieeexplore.ieee.org/search/freesrchabstract.jsp?navigation=no&arnumber=5687886},
   contact = {unger@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Over the past years research in pervasive computing has demonstrated the potential of context-aware and proactive technologies for improving human work performance and to ensure that people act compliant according to predefined regulations. Human work can be structured into tasks, whereas a task is representing an atomic human work entity. A person-centric flow is an IT-representation of the flow of activities an individual person is performing. For example the daily care schedule of a nurse can be understood as the person-centric flow of the nurse. To be able to effectively guide a person in a complex and highly dynamic work environment and to react on possible deviations from the flow the supporting system is required to be aware of the state of the person-centric-flow. Beside guidance the flow information can be utilized to check compliance of a person’s flow with prescribed sequences of operation. In this paper we propose a constraint-based workflow model for person-centric flows and an event-model which can be used to inform applications about the state of these flows.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-101&engl=1}
}
@inproceedings {INPROC-2010-100,
   author = {Hanna Eberle and Frank Leymann and Tobias Unger},
   title = {{Transactional Process Fragments - Recovery Strategies for Flexible Workflows with Process Fragments}},
   booktitle = {Proceedings of APSCC 2010},
   publisher = {IEEE Xplore},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--8},
   type = {Conference Paper},
   month = {December},
   year = {2010},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Transactional behavior in workflows was introduced to foster stable and foreseen workflow behavior, even in case a faulting situation occurs. Transactional behavior ensures that a workflow execution obtains a valid business state in the end, whatever faults might happen during execution. Flexibility concepts were introduced to be able to handle unforeseen situations in workflow executions. In this work we present recovery strategies for the flexibility workflow concept of process fragments. Our concept provides means to implement transactional behavior for process fragments, while preserving flexibility. Thereto, we specify two recovery strategies for process fragments: the backward recovery strategy allows to compensate already executed process fragments of the dynamically composed process. The forward recovery strategy handles the occurring faults by executing repair actions.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-100&engl=1}
}
@inproceedings {INPROC-2010-10,
   author = {Andreas Gehlert and Olha Danylevych and Dimka Karastoyanova},
   title = {{From Requirements to Executable Processes - A Literature Study.}},
   booktitle = {In Proceedings of the 5th International Workshop on Business Process Design (BPD 2009), Ulm, Germany, 7 September 2009},
   publisher = {BPD'09},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--11},
   type = {Workshop Paper},
   month = {January},
   year = {2010},
   keywords = {Requirement Engineering, Business Process Modelling, Process Merge},
   language = {English},
   cr-category = {D.2.2 Software Engineering Design Tools and Techniques,     D.2.13 Software Engineering Reusable Software,     H.4.1 Office Automation},
   contact = {olha.danylevych@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Service compositions are a major component to realize service-based applications (SBAs). The design of these service compositions follows mainly a process-modelling approach - an initial business process is refined until it can be executed on a workflow engine. Although this process-modelling approach proved to be useful, it largely disregards the knowledge gained in the requirements engineering discipline, e. g. in eliciting, documenting, managing and tracing requirements. Disregarding the requirements engineering phase may lead to undesired effects of the later service compositions such as lack of acceptance by the later users. To defuse this potentially critical issue we are interested in the interplay between requirements engineering and process modelling techniques. As a first step in this direction, we analyse the current literature in requirements engineering and process modelling in order to find overlaps where the techniques from both domains can be combined in useful ways. Our main finding is that scenario-based approaches from the requirements engineering discipline are a good basis for deriving executable processes. Depending whether the focus is on requirements engineering or on process design the inte-gration of the techniques are slightly different.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-10&engl=1}
}
@inproceedings {INPROC-2010-09,
   author = {Mirko Sonntag and Dimka Karastoyanova and Frank Leymann},
   title = {{The Missing Features of Workflow Systems for Scientific Computations}},
   booktitle = {Proceedings of the 3rd Grid Workflow Workshop (GWW), Software Engineering Conference, GI-Edition Lecture Notes in Informatics (LNI), P-160},
   publisher = {Gesellschaft f{\"u}r Informatik e.V. (GI)},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {209--216},
   type = {Workshop Paper},
   month = {February},
   year = {2010},
   isbn = {978-3-88579-254-3},
   keywords = {Business Workflow Management, Scientific Workflow Management},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   contact = {Mirko.Sonntag@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {This paper discusses technical aspects of how business workflow management systems can be improved in order to apply them in the field of scientific workflows and reap all their benefits. We give recommendations how to address the discovered gaps in support for scientific applications. The approach we follow addresses the requirements of scientists and scientific applications, which we also identify in this work.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-09&engl=1}
}
@inproceedings {INPROC-2010-07,
   author = {Thorsten Scheibler and Dieter Roller and Frank Leymann},
   title = {{Executing Pipes-and-Filters with Workflows}},
   booktitle = {ICIW 2010},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--6},
   type = {Conference Paper},
   month = {May},
   year = {2010},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://www.iaria.org/conferences2010/ICIW10.html},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In the context of Enterprise Application Integration (EAI) individual tasks have typically been implemented using specialized EAI-vendor technology based on messaging, and quite often customer-specific implementations. Those implementations prominently exploit the Pipes-and-Filters (PaF) architecture. This implementation approach is in conflict with the flow technology that is a cornerstone of the Service-Oriented Architecture (SOA) for solving integration problems. In this paper, we present how this conflict can be resolved. Therefore, we first analyse the differences between PaF architectures and (work-) flow approaches in general, and present the advantages and drawbacks of each solution. Afterwards, we describe how integration solutions modelled based on the PaF architecture can be implemented using flow technology by transforming the appropriate PaF patterns, in particular those used in EAI, into appropriate WS-BPEL constructs. We then present the results of appropriate tests that show that the performance of the corresponding workflows is superior to the mapping of PaF patterns to message flows. We finish off with outlining the additional tangible and non-tangible benefits that the Workflow Management System (WfMS) provides, such as monitoring. In a nut shell, we illustrate that the PaF architecture does not require an own implementation. It is sufficient to have a PaF modelling tool and then convert the appropriate},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-07&engl=1}
}
@inproceedings {INPROC-2010-04,
   author = {Thorsten Scheibler and Frank Leymann and Dieter Roller},
   title = {{From Pipes-and-Filters to Workflows}},
   booktitle = {The International Conference on Interoperability for Enterprise Software and Applications (I-ESA) 2010},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--10},
   type = {Conference Paper},
   month = {April},
   year = {2010},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The Pipes-and-Filters (PaF) Architecture has been prominently exploited in the context of Enterprise Application Integration (EAI). The individual tasks have typically been implemented using specialized EAI-vendor technology, message flows, and quite often customer-specific implementations. This implementation approach is in conflict with the flow technology that is a cornerstone of the Service-Oriented Architecture (SOA). We show in this paper how this conflict can be resolved. We first show how the PaF architecture can be implemented using flow technology by transforming the appropriate PaF patterns, in particular those used in EAI, into appropriate WS-BPEL constructs. We then present the results of appropriate tests that show that the performance of the corresponding workflows is superior to the mapping of PaF patterns to message flows. We finish off with outlining the additional tangible and non-tangible benefits that the Workflow Management System (WfMS) provides, such as monitoring. In a nut shell, we illustrate that the PaF architecture does not require an own implementation. It is sufficient to have a PaF modeling tool and then convert the appropriate models to workflows for execution by an appropriate WfMS.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-04&engl=1}
}
@inproceedings {INPROC-2010-03,
   author = {David Schumm and Frank Leymann and Zhilei Ma and Thorsten Scheibler and Steve Strauch},
   title = {{Integrating Compliance into Business Processes: Process Fragments as Reusable Compliance Controls}},
   booktitle = {Proceedings of the Multikonferenz Wirtschaftsinformatik (MKWI'10), G{\"o}ttingen, Germany, February 23-25, 2010},
   editor = {Schumann/Kolbe/Breitner/Frerichs},
   address = {G{\"o}ttingen},
   publisher = {Universit{\"a}tsverlag G{\"o}ttingen},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {2125--2137},
   type = {Conference Paper},
   month = {February},
   year = {2010},
   isbn = {978-3-941875-31-9},
   keywords = {Business Process Compliance, Process Fragment, Reusability},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   contact = {David.Schumm@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Companies increasingly have to pay attention to compliance concerns addressing business processes. Flexibly reacting to changing requirements coming from laws, regulations, and internal guidelines, becomes a necessary part of business process management. In this paper we propose the application of the emerging concept of process fragments in the field of compliance management in process-based applications. We exemplify realizing compliance requirements employing the notion of process fragments, and we show its characteristics and its practical application using a scenario common in industry. In doing so, we discuss how a fragment can be identified, which design considerations need to be taken into account, we discuss efficient storage and retrieval, and which ways of integration into business processes are feasible. This approach leverages the reusability of both, process models and realizations of compliance requirements.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-03&engl=1}
}
@inproceedings {INPROC-2010-01,
   author = {Branimir Wetzstein and Dimka Karastoyanova and Oliver Kopp and Frank Leymann and Daniel Zwink},
   title = {{Cross-Organizational Process Monitoring based on Service Choreographies}},
   booktitle = {Proceedings of the 25th Annual ACM Symposium on Applied Computing (SAC 2010); Sierre, Switzerland, 21-26 March, 2010},
   publisher = {ACM},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {2485--2490},
   type = {Conference Paper},
   month = {March},
   year = {2010},
   doi = {10.1145/1774088.1774601},
   keywords = {Business Activity Monitoring, Cross-Organizational Monitoring, Service Choreography},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   contact = {branimir.wetzstein@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Business process monitoring in the area of service oriented computing is typically performed using business activity monitoring technology in an intra-organizational setting. Due to outsourcing and the increasing need for companies to work together to meet their joint customer demands, there is a need for monitoring of business processes across organizational boundaries. Thereby, partners in a choreography have to exchange monitoring data, in order to enable process tracking and evaluation of process metrics. In this paper, we describe an event-based monitoring approach based on BPEL4Chor service choreography descriptions. We show how to define monitoring agreements specifying events each partner in the choreography has to provide. We distinguish between resource events and complex events for calculation of process metrics using complex event processing technology. We present our implementation and evaluate the concepts based on a scenario.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2010-01&engl=1}
}
@inproceedings {INPROC-2009-90,
   author = {Hanna Eberle and Oliver Kopp and Tobias Unger and Frank Leymann},
   title = {{Retry Scopes to Enable Robust Workflow Execution in Pervasive Environments}},
   booktitle = {Proceedings of the 2nd Workshop on Monitoring, Adaptation and Beyond (MONA+)},
   address = {Stockholm},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science},
   volume = {6275},
   pages = {358--369},
   type = {Workshop Paper},
   month = {November},
   year = {2009},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://www.s-cube-network.eu/MONA2/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Recent workflow languages are designed to serve the needs of business processes running in a unambiguous world based on unambiguous data. In contrast to business processes, processes running in a real world environment have to deal with data uncertainty and instability of the execution environment. Building a workflow language for real world flows based on a workflow language for business processes therefore may need additional modeling elements to be able to deal with this uncertainty and instability. Based on a real world process scenario we analyse and derive requirements for workflow language extensions for real world processes. The contributions provided by this paper are at first to investigate, how a workflow language can be extended properly followed up by the definition of workflow language extensions for real world processes, whereas the extensions are motivated by the real world process scenario. In this paper we use the Business Process Execution Language (BPEL) as extension foundation.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-90&engl=1}
}
@inproceedings {INPROC-2009-82,
   author = {Raman Kazhamiakin and Branimir Wetzstein and Dimka Karastoyanova and Marco Pistore and Frank Leymann},
   title = {{Adaptation of Service-Based Applications Based on Process Quality Factor Analysis}},
   booktitle = {Proceedings of the 2nd Workshop on Monitoring, Adaptation and Beyond (MONA+), co-located with ICSOC/ServiceWave 2009},
   publisher = {Online},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Workshop Paper},
   month = {November},
   year = {2009},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {When service-based applications implement business processes, it is important to monitor their performance in terms of Key Performance Indicators (KPIs). If monitoring results show that the KPIs do not reach target values, the influential factors have to be analyzed and corresponding adaptation actions have to be taken. In this paper we present a novel adaptation approach for service-based applications (SBAs) based on a process quality factor analysis. This approach uses decision trees for showing the dependencies of KPIs on process quality factors from different functional levels of an SBA. We extend the monitoring and analysis approach and show how the analysis results may be used to come up with an adaptation strategy leading to an SBA that satisfies KPI values. The approach includes creation of a model which associates adaptation actions to process quality metrics, extraction of adaptation requirements based on analysis results, and identification of an adaptation strategy which can consist of several adaptation actions on different functional levels of an SBA.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-82&engl=1}
}
@inproceedings {INPROC-2009-81,
   author = {Philipp Leitner and Branimir Wetzstein and Florian Rosenberg and Anton Michlmayr and Schahram Dustdar and Frank Leymann},
   title = {{Runtime Prediction of Service Level Agreement Violations for Composite Services}},
   booktitle = {Proceedings of the 3rd Workshop on Non-Functional Properties and SLA Management in Service-Oriented Computing, co-located with ICSOC 2009},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Workshop Paper},
   month = {November},
   year = {2009},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {SLAs are contractually binding agreements between service providers and consumers, mandating concrete numerical target values which the service needs to achieve. For service providers, it is essential to prevent SLA violations as much as possible to enhance customer satisfaction and avoid penalty payments. Therefore, it is desirable for providers to predict possible violations before they happen, while it is still possible to set counteractive measures. We propose an approach for predicting SLA violations at runtime, which uses measured and estimated facts (instance data of the composition or QoS of used services) as input for a prediction model. The prediction model is based on machine learning regression techniques, and trained using historical process instances. We present the architecture of our approach and a prototype implementation, and validate our ideas based on an illustrative example.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-81&engl=1}
}
@inproceedings {INPROC-2009-80,
   author = {Branimir Wetzstein and Philipp Leitner and Florian Rosenberg and Ivona Brandic and Schahram Dustdar and Frank Leymann},
   title = {{Monitoring and Analyzing Influential Factors of Business Process Performance}},
   booktitle = {Proceedings of the 13th IEEE Enterprise Distributed Object Conference (EDOC 2009)},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {September},
   year = {2009},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   contact = {branimir.wetzstein@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Business activity monitoring enables continuous observation of key performance indicators (KPIs). However, if things go wrong, a deeper analysis of process performance becomes necessary. Business analysts want to learn about the factors that influence the performance of business processes and most often contribute to the violation of KPI target values, and how they relate to each other. We provide a framework for performance monitoring and analysis of WS-BPEL processes, which consolidates process events and Quality of Service measurements. The framework uses machine learning techniques in order to construct tree structures, which represent the dependencies of a KPI on process and QoS metrics. These dependency trees allow business analysts to analyze how the process KPIs depend on lower-level process metrics and QoS characterisitics of the IT infrastructure. Deeper knowledge about the structure of dependencies can be gained by drill-down analysis of single factors of influence.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-80&engl=1}
}
@inproceedings {INPROC-2009-76,
   author = {Tobias Anstett and Dimka Karastoyanova and Frank Leymann and Ralph Mietzner and Ganna Monakova and Daniel Schleicher and Steve Strauch},
   title = {{MC-Cube: Mastering Customizable Compliance in the Cloud}},
   booktitle = {Proceedings of the 7th International Joint Conference on Service Oriented Computing, Stockholm, Sweden, November 23-27, 2009},
   editor = {Springer},
   publisher = {Springer Verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {592--606},
   type = {Conference Paper},
   month = {November},
   year = {2009},
   keywords = {Cloud Computing; IaaS; PaaS; SaaS; Monitoring; Enforcement},
   language = {English},
   cr-category = {H.2.7 Database Administration},
   contact = {anstett@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Outsourcing parts of a company's processes becomes more and more important in a globalized, distributed economy. While archi- tectural styles and technologies such as service-oriented architecture and Web services facilitate the distribution of business process over several departments, enterprises and countries, these business processes still need to comply with various regulations. These regulations can be company regulations, national, or international regulations. When outsourcing IT-functions, enterprises must ensure that the overall regulations are met. Therefore they need evidence from their outsourcing partners that supports the proof of compliance to regulations. Furthermore it must be possible to enforce the adherence to compliance rules at partners. In this paper we introduce so-called compliance interfaces that can be used by customers to subscribe to evidence at a provider and to enforce regulations at a provider. We introduce a general compliance architecture that allows compliance to be monitored and enforced at services deployed in any emerging cloud delivery model.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-76&engl=1}
}
@inproceedings {INPROC-2009-75,
   author = {Ralph Mietzner and Tobias Unger and Frank Leymann},
   title = {{Cafe: A Generic Configurable Customizable Composite Cloud Application Framework}},
   booktitle = {CoopIS 2009 (OTM 2009)},
   editor = {R. Meersman and T. Dillon and P. Herrero},
   address = {Berlin, Heidelberg},
   publisher = {Springer-Verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science},
   volume = {5870},
   pages = {357--364},
   type = {Conference Paper},
   month = {November},
   year = {2009},
   language = {English},
   cr-category = {K.4.4 Electronic Commerce,     H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In this paper we present Cafe (Composite Application Framework) an approach to describe configurable composite serviceoriented applications and to automatically provision them across different providers. Cafe enables independent software vendors to describe their composite service-oriented applications and the components that are used to assemble them. Components can be internal to the application or external and can be deployed in any of the delivery models present in the cloud. The components are annotated with requirements for the infrastructure they later need to be run on. Providers on the other hand advertise their infrastructure services by describing them as infrastructure capabilities. The separation of software vendors and providers enables end users and providers to follow a best-of-breed strategy by combining arbitrary applications with arbitrary providers. We show how such applications can be automatically provisioned and present an architecture and a prototype that implements the concepts.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-75&engl=1}
}
@inproceedings {INPROC-2009-74,
   author = {Annapaola Marconi and Marco Pistore and Adina Sirbu and Frank Leymann and Hanna Eberle and Tobias Unger},
   title = {{Enabling Adaptation of Pervasive Flows: Built-in Contextual Adaptation}},
   booktitle = {Service-Oriented Computing, 7th International Joint Conference,ICSOC-ServiceWave 2009, Stockholm, Sweden, November 24-27, 2009},
   editor = {Luciano Baresi and Chi-Hung Chi and Jun Suzuki},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science},
   volume = {5900},
   pages = {445--454},
   type = {Conference Paper},
   month = {November},
   year = {2009},
   isbn = {978-3-642-10382-7},
   doi = {10.1007/978-3-642-10383-4_33},
   keywords = {Adaption; Adaptation; Business Process Management; Flexibility},
   language = {English},
   cr-category = {D.2.2 Software Engineering Design Tools and Techniques,     F.4.1 Mathematical Logic},
   ee = {http://www.springerlink.com/content/8qn3xq57n3787ru4/},
   contact = {unger@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Adaptable pervasive flows are dynamic workflows situated in the real world that modify their execution in order to adapt to changes in the execution environment. This requires on the one hand that a flow must be context-aware and on the other hand that it must be flexible enough to allow an easy and continuous adaptation. In this paper we propose a set of constructs and principles for embedding the adaptation logic within the specification of a flow. Moreover, we show how a standard language for web process modeling (BPEL) can be extended to support the proposed built-in adaptation constructs.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-74&engl=1}
}
@inproceedings {INPROC-2009-73,
   author = {Hanna Eberle and Tobias Unger and Frank Leymann},
   title = {{Process Fragments}},
   booktitle = {On the Move to Meaningful Internet Systems: OTM 2009, Part I},
   editor = {R. Meersman and T. Dillon and P. Herrero},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science},
   volume = {5870},
   pages = {398--405},
   type = {Conference Paper},
   month = {November},
   year = {2009},
   doi = {10.1007/978-3-642-05148-7_29},
   keywords = {Process Managment; Process Adaption; Process Flexibility},
   language = {English},
   cr-category = {D.2.2 Software Engineering Design Tools and Techniques,     F.4.1 Mathematical Logic},
   contact = {hanna.eberle@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The concepts presented in this paper are motivated by the assumption that process knowledge is distributed knowledge and not completely known just by one person. Driven by this assumption we deal in this paper with the following questions: How can partial process knowledge be represented? How can this partial knowledge be used to define something more complete? To use higher level artefacts as building blocks to new applications has a long tradition in software engineering to increase flexibility and reduce modeling costs. In this paper we take a first step in applying this concept to processes, by defining process building blocks and operations which compose process building blocks. The building blocks will be referred to as process fragments in the following. The process fragment composition may take place either at design or runtime of the process. The design time approach reduces design costs by reusing artefacts. However the runtime fragment composition approach realizes high flexibility due to the possibility in the dynamic selection of the fragments to be composed. The contribution of this work lies in a fragment definition that enables the fragment modeler to represent his ’local’ and fragmentary knowledge in a formal way and which allows fragment models to be composed.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-73&engl=1}
}
@inproceedings {INPROC-2009-72,
   author = {Oliver Kopp and Ralph Mietzner and Frank Leymann},
   title = {{The Influence of an External Transaction on a BPEL Scope}},
   booktitle = {CoopIS 2009 (OTM 2009)},
   editor = {R. Meersman and T. Dillon and P. Herrero},
   address = {Berlin, Heidelberg},
   publisher = {Springer-Verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science},
   volume = {5870},
   pages = {381--388},
   type = {Conference Paper},
   month = {November},
   year = {2009},
   doi = {10.1007/978-3-642-05148-7_27},
   language = {English},
   cr-category = {K.4.4 Electronic Commerce,     H.4.1 Office Automation},
   ee = {http://www.onthemove-conferences.org/index.php/coopis,     http://www.onthemove-conferences.org},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Business processes constitute an integral part of today's IT applications. They contain transactions as essential building blocks to ensure integrity and all-or-nothing behavior. The Business Process Execution Language is the dominant standard for modeling and execution of business processes in a Web service environment. BPEL itself contains a transaction model based on compensation, that describes the (local) transactions in a business process. The WS-Coordination framework deals with (external) transactions between Web services and is used to define the transaction behavior between a BPEL process and its partners. In this paper, we investigate how external transactions between Web services interrelate with local transactions of BPEL.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-72&engl=1}
}
@inproceedings {INPROC-2009-70,
   author = {Daniel Schleicher and Tobias Anstett and Frank Leymann and Ralph Mietzner},
   title = {{Maintaining Compliance in Customizable Process Models}},
   booktitle = {Proceedings of the 17th International Conference on COOPERATIVE INFORMATION SYSTEMS (CoopIS 2009)},
   editor = {Robert Meersman and Tharam Dillon and Pilar Herrero},
   address = {Heidelberg},
   publisher = {Springer Verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science},
   volume = {5870},
   pages = {60--75},
   type = {Conference Paper},
   month = {November},
   year = {2009},
   isbn = {978-3-642-05147-0},
   keywords = {Compliance; Business process modeling},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   contact = {daniel.schleicher\#n.o.s.p.a.m@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Compliance of business processes has gained importance during the last years. The growing number of internal and external regulations that companies need to obey has led to this state. This paper presents a practical concept of ensuring compliance during design time of customizable business processes. We introduce the concept of a business process template that implicitly contains compliance constraints as well as points of variability. We further present an algorithm that ensures that these constraints cannot be violated. We also show how these algorithms can be used to check whether a customization of this process template is valid regarding these compliance constraints. So the designer of a business process, in contrast to the template designer, does not have to worry about compliance of the eventual process. In a final step we show how these general concepts can be applied to WS-BPEL.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-70&engl=1}
}
@inproceedings {INPROC-2009-67,
   author = {Oliver Kopp and Matthias Wieland and Frank Leymann},
   title = {{External and Internal Events in EPCs: e2EPCs}},
   booktitle = {2nd International Workshop on Event-Driven Business Process Management (edBPM09)},
   publisher = {Springer Verlag},
   institution = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   series = {Lecture Notes in Business Information Processing},
   volume = {43},
   pages = {381--392},
   type = {Workshop Paper},
   month = {September},
   year = {2009},
   doi = {10.1007/978-3-642-12186-9_36},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://icep-edbpm09.fzi.de/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The notion of event-driven process chains (EPC) is widely used to model processes. It is an ongoing discussion of how to reach executable workflows from EPCs. While the transformation of the general structure and the functions is well-understood, the transformation of events is an open issue. This paper discusses different possible event types and their semantics. Furthermore, it presents a transformation of the introduced event types to workflow constructs respecting the semantics of each event.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-67&engl=1}
}
@inproceedings {INPROC-2009-65,
   author = {Frank Leymann},
   title = {{Cloud Computing: The Next Revolution in IT}},
   booktitle = {Proc. 52th Photogrammetric Week},
   publisher = {Wichmann Verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {3--12},
   type = {Conference Paper},
   month = {September},
   year = {2009},
   isbn = {978-3-87907-483-9},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://www.ifp.uni-stuttgart.de/phowo/index.en.html,     http://www.vde-verlag.de/buecher/537483/photogrammetric-week-09.html,     http://www.ifp.uni-stuttgart.de/publications/phowo09/phowo09.en.htm},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Cloud computing provides a new mode of use and of offer of IT resources. Such resources can be used “on demand” by anybody who has access to the internet. The resources are offered in a “utility-like” manner by providers based on actual-use-based prices. It is expected that cloud computing will change the way how organizations will use IT and think about IT: ultimately, cloud computing may relieve organizations from owning their own IT environment. In this article we show that cloud computing can be seen as the next step in an evolution from isolated computers over clusters and beyond grids. We suggest a definition of clouds by abstracting their most important characteristics. The current set of cloud offerings is organized in a layered structure, and we propose an additional layer on top of that allowing to build applications in a composite manner (“composite as a service”). The distributed architecture of such composite cloud applications is derived by considering the structure of the individual services being composed. Finally, we argue that predefined points-of-variability are of utmost importance for cloud applications to be able to easily adapt them to the different requirements of the huge number of cloud customers.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-65&engl=1}
}
@inproceedings {INPROC-2009-64,
   author = {Matthias Wieland and Uwe-Philipp K{\"a}ppeler and Paul Levi and Frank Leymann and Daniela Nicklas},
   title = {{Towards Integration of Uncertain Sensor Data into Context-aware Workflows}},
   booktitle = {Tagungsband INFORMATIK 2009 – Im Focus das Leben, 39. Jahrestagung der Gesellschaft f{\"u}r Informatik e.V. (GI)},
   editor = {GI-Edition Lecture Notes in Informatics (LNI)},
   address = {L{\"u}beck},
   publisher = {Lecture Notes in Informatics (LNI)},
   institution = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   type = {Workshop Paper},
   month = {September},
   year = {2009},
   language = {English},
   cr-category = {H.4 Information Systems Applications},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Image Understanding;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The integration and usage of uncertain sensor data in workflows is a difficult problem. In this paper we describe these difficulties which result from the combination of very distinct areas. On the one hand, applications from area of measurement engineering manage sensors that capture data and annotate the data with technical meta data. On the other hand, context-aware workflows from the BPM area place high level requirements for the quality of context data that is derived from the sensor data. Between those two areas exists a gap that has to be closed by a context management and mediation system, supporting the handling of Quality of Context (QoC). To achieve this the paper presents an QoC aware architecture based on an extension of the existing Nexus Platform and a first approach for matching the workflow requirements with the sensor annotations.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-64&engl=1}
}
@inproceedings {INPROC-2009-63,
   author = {Matthias Wieland and Carsten L{\"a}ngerer and Frank Leymann and Oliver Siemoneit and Christoph Hubig},
   title = {{Methods for Conserving Privacy in Workflow Controlled Smart Environments - A Technical and Philosophical Enquiry into Human-Oriented System Design of Ubiquitous Work Environments}},
   booktitle = {Proceedings of the The Third International Conference on Mobile Ubiquitous Computing, Systems, Services and Technologies, UBICOMM 2009},
   address = {Sliema, Malta},
   publisher = {IEEE},
   institution = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   pages = {16--21},
   type = {Conference Paper},
   month = {October},
   year = {2009},
   keywords = {context-aware workflow systems; human tasks; privacy; ethics; humane system design},
   language = {English},
   cr-category = {J Computer Applications,     K Computing Milieu,     H.4 Information Systems Applications},
   department = {University of Stuttgart, Institute of Architecture of Application Systems;     Universit{\"a}t Stuttgart, Institut f{\"u}r Philosophie, Abteilung f{\"u}r Wissenschaftstheorie und Technikphilosophie (IP/WTTP)},
   abstract = {In the last years context-aware workflow systems have gained more and more importance. However, in research little emphasis has been put on workplace privacy and humane system design. It is the aim of this paper to give an overview on the effects of combining workflow systems and context-aware systems and to discuss its implications for workplace privacy and human-oriented design. Different methods are to be depicted that help to overcome certain ethical problems thus allowing for the development of acceptable, justified and justifiable technical solutions which are likely to be also adopted by its latter users. Finally a ``best practice'' prototype is to be presented which implements the introduced methods.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-63&engl=1}
}
@inproceedings {INPROC-2009-54,
   author = {Dimka Karastoyanova and Frank Leymann},
   title = {{BPEL’n’Aspects: Adapting Service Orchestration Logic}},
   booktitle = {Proceedings of 7th International Conference on Web Services (ICWS 2009)},
   address = {Los Angeles, CA, USA},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {July},
   year = {2009},
   doi = {10.1109/ICWS.2009.75},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   contact = {dimka.karastoyanova@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The need for flexibility in process-based applications, in particular during their execution, places the demand for enabling adaptability of processes. AOP is considered to be one of the approaches to flexibly switch on and off functionality on per-instance basis in applications during their execution; analogously, this paradigm can be applied in a BPEL environment to enable adaptation of running orchestrations. In the presented approach we strive towards reuse of as much concepts and technology already available in a Web service (WS) environment as possible. We combine standard BPEL, the publish/subscribe paradigm and WS-Policy so that WS operations play the role of aspects with respect to BPEL processes. We present the syntax for such aspects as an extension of the WS-Policy framework. We introduce the architecture of the supporting infrastructure and a prototypical implementation. The approach draws on the combined benefits of service orientation and the AOP paradigm to improve the state-of-the-art techniques for flexibility of service orchestrations in a non-intrusive manner.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-54&engl=1}
}
@inproceedings {INPROC-2009-53,
   author = {Nazario Cipriani and Matthias Wieland and Matthias Grossmann and Daniela Nicklas},
   title = {{Tool Support for the Design and Management of Spatial Context Models}},
   booktitle = {Proc. of the 13th East European Conference on Advances in Databases and Information Systems (ADBIS 2009)},
   address = {Riga, Lativa},
   publisher = {Springer},
   institution = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   type = {Conference Paper},
   month = {September},
   year = {2009},
   language = {English},
   cr-category = {H.2.4 Database Management Systems},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {A central task in the development of context-aware applications is the modeling and management of complex context information. In this paper, we present the NexusEditor, which eases this task by providing a graphical user interface to design schemas for spatial context models, interactively create queries, send them to a server and visualize the results. One main contribution is to show how schema awareness can improve such a tool: the NexusEditor dynamically parses the underlying data model and provides additional syntactic checks, semantic checks, and short-cuts based on the schema information. Furthermore, the tool helps to design new schema definitions based on the existing ones, which is crucial for an iterative and user-centric development of context-aware applications. Finally, it provides interfaces to existing information spaces and visualization tools for spatial data like GoogleEarth.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-53&engl=1}
}
@inproceedings {INPROC-2009-52,
   author = {Matthias Wieland and Katharina G{\"o}rlach and David Schumm and Frank Leymann},
   title = {{Towards Reference Passing in Web Service and Workflow-based Applications}},
   booktitle = {Proceedings of the 13th IEEE Enterprise Distributed Object Conference (EDOC 2009)},
   address = {Auckland, New Zealand},
   publisher = {IEEE},
   institution = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   pages = {109--118},
   type = {Conference Paper},
   month = {September},
   year = {2009},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures,     H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In a Service-Oriented Architecture (SOA) based on Web Service technology the services typically communicate with each other by passing data values directly from one service to another. In the case the services are orchestrated by workflows the services receive their input values from the workflow engine and return their calculated results back to the engine by value. In this paper we show several use cases where such value passing behavior has drawbacks. To address this challenge we introduce the concept of pointers in SOA. Pointers allow services to pass their data by reference which is a fundamental advantage for Web Service communication. Furthermore we show an extension of BPEL that introduces reference variables as new type of data containers in workflows. In addition, for the management of pointers we present the Reference Resolution System which can be used in very flexible setups either as central or distributed system.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-52&engl=1}
}
@inproceedings {INPROC-2009-50,
   author = {Ralph Mietzner and Tobias Unger and Robert Titze and Frank Leymann},
   title = {{Combining Different Multi-Tenancy Patterns in Service-Oriented Applications}},
   booktitle = {Proceedings of the 13th IEEE Enterprise Distributed Object Conference (EDOC 2009)},
   editor = {IEEE Computer Society},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {131--140},
   type = {Conference Paper},
   month = {October},
   year = {2009},
   isbn = {978-0-7695-3785-6},
   doi = {10.1109/EDOC.2009.13},
   keywords = {multi-tenancy; SaaS; services; SOA; composite applications},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures,     H.4.1 Office Automation},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2009-50/INPROC-2009-50.pdf,     http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5277698},
   contact = {ralph.mietzner@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Software as a service (SaaS) providers exploit economies of scale by offering the same instance of an application to multiple customers typically in a single-instance multitenant architecture model. Therefore the applications must be scalable, multi-tenant aware and configurable. In this paper we show how the services in a service-oriented SaaS application can be deployed using different multi-tenancy patterns. We describe how the chosen patterns influence the customizability, multi-tenant awareness and scalability of the application. Using the patterns we describe how individual services in a multitenant aware application can be not multi-tenant aware while maintaining the overall multi-tenant awareness of the application. We show based on a real-world example how the patterns can be used in practice and show how existing applications already use these patterns.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-50&engl=1}
}
@inproceedings {INPROC-2009-49,
   author = {Marc Bischof and Oliver Kopp and Tammo van Lessen and Frank Leymann},
   title = {{BPELscript: A Simplified Script Syntax for WS-BPEL 2.0}},
   booktitle = {2009 35th Euromicro Conference on Software Engineering and Advanced Applications (SEAA 2009)},
   publisher = {IEEE Computer Society Press},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {39--46},
   type = {Conference Paper},
   month = {August},
   year = {2009},
   doi = {10.1109/SEAA.2009.21},
   keywords = {service orchestration; service scripting; BPEL; BPM lifecycle},
   language = {English},
   cr-category = {D.1.1 (Applicative Functional) Programming,     D.3.4 Programming Languages Processors,     H.4.1 Office Automation,     K.1 The Computer Industry},
   ee = {http://seaa2009.vtt.fi/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Business processes are usually modeled using graphical notations such as BPMN. As a first step towards execution as workflow, a business process is transformed to an abstract WS-BPEL process. Technical details required for execution are added by an IT expert. While IT experts expect Java-like syntax for programs, WS-BPEL requires processes to be expressed in XML. This paper introduces BPELscript as a new syntax for WS-BPEL aiming to reduce the barrier for IT experts to use WS-BPEL by providing a JavaScript-inspired syntax.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-49&engl=1}
}
@inproceedings {INPROC-2009-48,
   author = {Hanna Eberle and Stefan F{\"o}ll and Klaus Herrmann and Frank Leymann and Annapaola Marconi and Tobias Unger and Hannes Wolf},
   title = {{Enforcement from the Inside: Improving Quality of Business in Process Management}},
   booktitle = {2009 IEEE International Conference on Web Services (ICWS 2009)},
   address = {Los Alamitos, CA, USA},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {405--412},
   type = {Conference Paper},
   month = {July},
   year = {2009},
   doi = {10.1109/ICWS.2009.82},
   isbn = {978-0-7695-3709-2},
   keywords = {Business Process Management; BPM; BPEL; Enforcement},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2009-48/INPROC-2009-48.pdf,     http://ieeexplore.ieee.org/search/wrapper.jsp?arnumber=5175850,     http://www2.computer.org/portal/web/csdl/doi/10.1109/ICWS.2009.82},
   contact = {unger@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems;     University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {In this paper we introduce a new modeling tool for constraint handling in the area of workflow technology. The constraint handlers can be used to improve the quality of business processes but without changing already existing business logic. Todays workflow languages provide no possibility to model constraints and the actions in case the constraints get violated explicitly. Fault and event handling mechanisms to react to events not expected in normal executions are only provided by the BPEL language. Using BPEL as workflow language we integrate the constraint handling extension without changing any existing semantics in a smart way. In our approach we use this fault and event handling mechanisms to extend the BPEL language with a constraint handling mechanism. By integrating this constraint handling tool into the BPEL language we provide an approach for quality driven process modeling with the BPEL language.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-48&engl=1}
}
@inproceedings {INPROC-2009-41,
   author = {Tobias Anstett and Frank Leymann and Ralph Mietzner and Steve Strauch},
   title = {{Towards BPEL in the Cloud: Exploiting Different Delivery Models for the Execution of Business Processes}},
   booktitle = {Proceedings of the International Workshop on Cloud Services (IWCS 2009) in conjunction with the 7th IEEE International Conference on Web Services (ICWS 2009), Los Angeles, CA, USA, July 10, 2009},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {670--677},
   type = {Workshop Paper},
   month = {July},
   year = {2009},
   keywords = {BPEL; Cloud Computing; SaaS; PaaS; IaaS; Security; Trust},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {More and more companies are outsourcing parts of their business processes to third party providers to exploit the expertise and economies of scale of these third party providers. In the IT field, emerging delivery models for software such as Software as a Service and cloud computing offer the possibility to outsource applications and computing infrastructure and thus enable enterprises to focus on their core competences. In this paper we investigate how the new delivery models affect the outsourcing of business processes modeled in WS-BPEL. WS-BPEL is the standard to model and execute business processes in Web service-based IT landscapes. We describe how security and trust issues affect the execution of BPEL processes in the cloud and show the requirements on the middleware supporting the execution of BPEL processes.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-41&engl=1}
}
@inproceedings {INPROC-2009-40,
   author = {Ralph Mietzner and Tammo van Lessen and Alexander Wiese and Matthias Wieland and Dimka Karastoyanova and Frank Leymann},
   title = {{Virtualizing Services and Resources with ProBus: The WS-Policy-Aware Service and Resource Bus}},
   booktitle = {Proceedings of the 7th International Conference on Web Services (ICWS) 2009},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {July},
   year = {2009},
   keywords = {WS-Policy; WSRF; Enterprise Service Bus; ESB; Service Selection},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {A fundamental principle of service oriented architectures is the decoupling of service requesters and service providers to enable late binding of services at deployment time or even dynamic binding of services at runtime. This is important in enterprise settings, where different services that implement business functions in critical business processes are dynamically chosen based on availability or price. The same problem also applies to dynamic Grid environments where resources need to be dynamically chosen based on availability and other non-functional properties. The WS-Policy framework describes how policies for both providers and requesters are specified to allow the selection of services based on these policies. Existing approaches, using WS-Policy, have drawbacks by placing the burden of the service selection partially on the client. In this paper we present an approach to extend an enterprise service bus that allows service clients to submit policies the service provider needs to comply with directly in the message that triggers the service invocation. We show how these policies are evaluated in the bus and how policies are defined for not only stateless services, but also stateful resources.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-40&engl=1}
}
@inproceedings {INPROC-2009-34,
   author = {Ganna Monakova and Oliver Kopp and Frank Leymann},
   title = {{Improving Control Flow Verification in a Business Process using an Extended Petri Net}},
   booktitle = {Proceedings of the 1st Central-European Workshop on Services and their Composition (ZEUS 2009)},
   editor = {Oliver Kopp and Niels Lohmann},
   address = {Stuttgart},
   publisher = {CEUR-WS.org},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {95--101},
   type = {Workshop Paper},
   month = {March},
   year = {2009},
   keywords = {petri net extension; data dependency},
   language = {English},
   cr-category = {I.6 Simulation and Modeling,     H.4.1 Office Automation},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2009-34/INPROC-2009-34.pdf,     http://www.iaas.uni-stuttgart.de/zeus,     http://ceur-ws.org/Vol-438/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In a business process, control flow decisions are based on the evaluation of conditions. Thus, conditions must be considered for control flow veri cation. This paper shows how the Petri nets based control fl ow veri cation can be improved by analysing conditions and logical relations between them. We outline a Petri net extension with predicate transitions, which are responsible for conditions evaluation based on the collected knowledge, and effect places, which contain fact tokens representing the effects of certain operations and decisions made.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-34&engl=1}
}
@inproceedings {INPROC-2009-33,
   author = {Ganna Monakova and Oliver Kopp and Frank Leymann and Simon Moser and Klaus Sch{\"a}fers},
   title = {{Verifying Business Rules Using an SMT Solver for BPEL Processes}},
   booktitle = {Proceedings of the Business Process and Services Computing Conference: BPSC'09},
   publisher = {Gesellschaft f{\"u}r Informatik e.V. (GI)},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Informatics},
   type = {Conference Paper},
   month = {March},
   year = {2009},
   isbn = {978-3-88579-241-3},
   keywords = {constraint verification},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {https://sabreconference.wifa.uni-leipzig.de/frontend/index.php?page_id=450,     http://subs.emis.de/LNI/Proceedings/Proceedings147/article2475.html},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {WS-BPEL is the standard for modelling executable business processes. Recently, verification of BPEL processes has been an important topic in the research community. While most of the existing approaches for BPEL process verification merely consider control-flow based analysis, some actually consider data-flows, but only in a very restrictive manner. In this paper, we present a novel approach that combines control-flow analysis and data-flow analysis, producing a logical representation of a process model. This logical representation captures the relations between process variables and execution paths that allow properties to be verified using Satisfiability Modulo Theory (SMT) solvers under constraints represented by the modelled assertions.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-33&engl=1}
}
@inproceedings {INPROC-2009-31,
   author = {Oliver Kopp and Frank Leymann},
   title = {{Do We Need Internal Behavior in Choreography Models?}},
   booktitle = {Proceedings of the 1st Central-European Workshop on Services and their Composition, ZEUS 2009, Stuttgart, Germany, March 2--3, 2009},
   editor = {Oliver Kopp and Niels Lohmann},
   address = {Stuttgart},
   publisher = {CEUR-WS.org},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {CEUR Workshop Proceedings},
   volume = {438},
   pages = {68--73},
   type = {Workshop Paper},
   month = {March},
   year = {2009},
   issn = {1613-0073},
   keywords = {Choreography; WS-CDL; BPEL4Chor},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2009-31/INPROC-2009-31.pdf,     http://www.iaas.uni-stuttgart.de/zeus,     http://ceur-ws.org/Vol-438/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Choreographies capture the message exchanges between multiple processes. Certain choreography languages ignore the internal behavior completely, other languages offer the possibility to model internal behavior. This paper presents an example modeled in both types of languages and discusses the need to integrate internal behavior in choreographies.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-31&engl=1}
}
@inproceedings {INPROC-2009-30,
   author = {Florian Daniel and Fabio Casati and Vincenzo D'Andrea and Steve Strauch and David Schumm and Frank Leymann and Emmanuel Mulo and Uwe Zdun and Schahram Dustdar and Samir Sebahi and Fabien de Marchi and Mohand-Said Hacid},
   title = {{Business Compliance Governance in Service-Oriented Architectures}},
   booktitle = {Proceedings of the IEEE Twenty-Third International Conference on Advanced Information Networking and Applications (AINA'09), Bradford, United Kingdom, May 26-29, 2009},
   editor = {Irfan Awan and Muhammad Younas and Takahiro Hara and Arjan Durresi},
   address = {Los Alamitos, California},
   publisher = {IEEE Press},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {113--120},
   type = {Conference Paper},
   month = {May},
   year = {2009},
   isbn = {978-1-4244-4000-9},
   keywords = {Compliance, Process Fragments, SOA, Compliance governance, Business process management, View-based modeling},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Governing business compliance with regulations, laws, best practices, contracts, and the like is not an easy task, and so far there are only limited software products available that help a company to express compliance rules and to analyze its compliance state. We argue that today’s SOA-based way of implementing and conducting business (e.g., using Web services and business process engines) lends itself very well to the development of a comprehensive compliance government solution that effectively aids companies in being compliant. In this paper, we contextualize the compliance problem in SOA-based businesses, we highlight which are the most salient research challenges that need to be addressed, and we describe our approach to compliance governance, spanning design, execution, and evaluation concerns.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-30&engl=1}
}
@inproceedings {INPROC-2009-28,
   author = {Oliver Kopp and Matthias Wieland and Frank Leymann},
   title = {{Towards Choreography Transactions}},
   booktitle = {Proceedings of the 1st Central-European Workshop on Services and their Composition, ZEUS 2009, Stuttgart, Germany, March 2--3, 2009},
   editor = {Oliver Kopp and Niels Lohmann},
   address = {Stuttgart},
   publisher = {CEUR-WS.org},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {CEUR Workshop Proceedings},
   volume = {438},
   pages = {49--54},
   type = {Workshop Paper},
   month = {March},
   year = {2009},
   issn = {1613-0073},
   keywords = {WS-BPEL; BPEL; BPEL4Chor; Transactions; Choreography; 2PC; Sphere},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2009-28/INPROC-2009-28.pdf,     http://www.iaas.uni-stuttgart.de/zeus,     http://ceur-ws.org/Vol-438/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The focus of choreography modeling is to capture the message exchange between processes. Common choreography modeling languages do not provide capabilities to group activities of different participants together into an all-or-nothing group. This paper presents choreography spheres as a modeling technique for cross-process transactions based on BPEL4Chor and sketches a mapping to BPEL.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-28&engl=1}
}
@inproceedings {INPROC-2009-27,
   author = {David Schumm and Dimka Karastoyanova and Frank Leymann and J{\"o}rg Nitzsche},
   title = {{On Visualizing and Modelling BPEL with BPMN}},
   booktitle = {IEEE Proceedings of the 4th International Workshop on Workflow Management (IWWM2009)},
   editor = {Henning M{\"u}ller and Jinjun Chen and Massimo Cafaro and Jong Hyuk Park and Nabil Abdennadher},
   address = {Los Alamitos, California},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {80--87},
   type = {Workshop Paper},
   month = {May},
   year = {2009},
   isbn = {978-0-7695-3677-4},
   keywords = {BPEL; BPMN; Modelling; Visualizing},
   language = {English},
   cr-category = {D.2.2 Software Engineering Design Tools and Techniques,     H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The advantages of the process-based approach to implementing applications lead to the development of notations for modelling business processes and languages for enacting them in a process engine for the purpose of process automation. Currently the Business Process Modeling Notation (BPMN) is typically used for modelling business processes and the Business Process Execution Language (BPEL) is used as the process execution format. Both languages differ in purpose, expressivity and operational semantics. Recently it has been shown that there is no complete bi-directional mapping between BPMN and BPEL and transformations have been defined between the two formalisms. However, these transformations lead to more complex models in both, BPEL and BPMN, and enable a roundtrip for only a limited number of scenarios. In this paper we show how BPEL processes can be modelled using the graphical aspect of BPMN in order to facilitate modelling of executable processes using BPMN while avoiding model transformations.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-27&engl=1}
}
@inproceedings {INPROC-2009-26,
   author = {Daniel Wutke and Daniel Martin and Frank Leymann},
   title = {{A Method for Partitioning BPEL Processes for Decentralized Execution}},
   booktitle = {Proceedings of the 1st Central-European Workshop on Services and their Composition, ZEUS 2009, Stuttgart, Germany, March 2--3, 2009.},
   editor = {Oliver Kopp and Niels Lohmann},
   address = {Stuttgart},
   publisher = {CEUR-WS.org},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {CEUR Workshop Proceedings},
   volume = {438},
   pages = {109--114},
   type = {Workshop Paper},
   month = {March},
   year = {2009},
   issn = {1613-0073},
   keywords = {BPEL; EWFN; Process partitioning; decentralized process enactment},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://CEUR-WS.org/Vol-438/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Service orchestrations are a common means to compose individual services to either higher-level services or potentially complex composite applications. The Web Service Business Process Execution Language (WS-BPEL) is an example for a language that allows for de - ning automatically executable orchestrations of Web services. As of today, BPEL process are typically executed in a centralized manner; the process model is deployed on a single work ow management system which, during process instance execution, interprets the process de nition and interacts with the orchestrated Web services on behalf of the user. In previous work, we have presented an approach which enables decentralized execution of BPEL processes based on a decentralized process model and supporting runtime infrastructure. In this paper we describe a method for automatic splitting of a process among the partners participating in its execution, referred to as process partitioning.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-26&engl=1}
}
@inproceedings {INPROC-2009-25,
   author = {Tammo van Lessen and J{\"o}rg Nitzsche and Dimka Karastoyanova},
   title = {{Facilitating Rich Data Manipulation in BPEL using E4X}},
   booktitle = {Proceedings of the 1st Central-European Workshop on Services and their Composition, ZEUS 2009, Stuttgart, Germany, March 2--3, 2009},
   editor = {Oliver Kopp and Niels Lohmann},
   address = {Stuttgart},
   publisher = {CEUR-WS.org},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {CEUR Workshop Proceedings},
   volume = {438},
   pages = {102--108},
   type = {Workshop Paper},
   month = {March},
   year = {2009},
   issn = {1613-0073},
   keywords = {WS-BPEL; BPEL; JavaScript; E4X; ECMAScript; XML},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2009-25/INPROC-2009-25.pdf},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The Business Process Execution Language (BPEL) uses XML to specify the data used within a process and realizes data flow via (globally) shared variables. Additionally, assign activities can be used to copy (parts of) variables to other variables using techniques like XPath or XSLT. Although BPEL’s built-in functionality is sufficient for simple data manipulation tasks, it becomes very cumbersome when dealing with more sophisticated data models, such as arrays. ECMAScript for XML (E4X) extends JavaScript with support for XML-based data manipulation by introducing new XPath-like language features. In this paper we show how E4X can help to significantly ease data manipulation tasks and propose a BPEL extension that allows employing JavaScript/E4X for implementing them. As E4X allows defining custom functions in terms of scripts, reusability with respect to data manipulation is improved. To verify the conceptual framework we present a proof-of-concept implementation based on Apache ODE.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-25&engl=1}
}
@inproceedings {INPROC-2009-23,
   author = {Branimir Wetzstein and Steve Strauch and Frank Leymann},
   title = {{Measuring Performance Metrics of WS-BPEL Service Compositions}},
   booktitle = {Proceedings of the Fifth International Conference on Networking and Services (ICNS 2009), Valencia, Spain, April 20-25, 2009},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {April},
   year = {2009},
   keywords = {KPI, Performance Measurement, Process Performace Metric, WS-BPEL, Service Composition},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In this paper we present an approach to the development of monitoring solutions for processes implemented as WSBPEL service compositions. The approach allows modeling of process performance metrics in a platform-independent manner and then generating an event-based monitor model for a specific WS-BPEL process engine. We create a metamodel which enables modeling of different types of process performance metrics. In particular, our approach supports modeling of metrics related to correlated processes. In the deployment phase, we generate a monitor model based on a proprietary event metamodel of a process engine. In addition, we determine which events are needed for the calculation of PPMs, and generate corresponding deployment information for the process engine.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-23&engl=1}
}
@inproceedings {INPROC-2009-22,
   author = {Zhilei Ma and Wei Lu and Frank Leymann},
   title = {{Query Structural Information of BPEL Processes}},
   booktitle = {Proceedings of the Fourth International Conference on Internet and Web Applications and Services (ICIW 2009), Venice/Mestre, Italy, May 24-28, 2009},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--6},
   type = {Conference Paper},
   month = {May},
   year = {2009},
   keywords = {BPEL; query; repository; inexact matchmaking; graph theory},
   language = {English},
   cr-category = {G.2.2 Discrete Mathematics Graph Theory,     G.4 Mathematical Software,     H.2.4 Database Management Systems,     H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Reuse of proven process models can increase modeling efficient by avoiding reinvent the wheel and ensure the quality of process models. To provide a better support for reuse, the retrieve mechanism of a process repository should be able to propose similar process models that ranked according to their similarity degrees to users for reuse by modification or customization. As a process model and a query model can both be viewed as rooted, directed, and acyclic graphs, the problem of querying structural information of BPEL processes has reduced to a graph matchmaking problem. In this paper we present a novel and efficient graph-based algorithm for querying structural information of BPEL processes based on an inexact matchmaking semantics. Our algorithm performs in the worst case in polynomial time in the orders of the query graph and the process graph.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-22&engl=1}
}
@inproceedings {INPROC-2009-21,
   author = {Zhilei Ma and Frank Leymann},
   title = {{BPEL Fragments for Modularized Reuse in Modeling BPEL Processes}},
   booktitle = {The Fifth International Conference on Networking and Services (ICNS 2009), Valencia, Spain, April 20-25, 2009},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {63--68},
   type = {Conference Paper},
   month = {April},
   year = {2009},
   doi = {10.1109/ICNS.2009.76},
   keywords = {BPEL; BPEL fragment; process fragment; reuse; business process modeling},
   language = {English},
   cr-category = {H.1 Models and Principles},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {BPEL has been established as the standard for modeling business processes by orchestratingWeb services. When modeling a BPEL process, users end up in basically three approaches: from scratch, by using a process template or a reference process, and by ad hoc modifying a existing process model to meet the current requirements. There is strong demand on a flexible and modularized approach for reusing BPEL process models. As neither the BPEL standard nor the current BPEL extensions support such a feature for reuse, we present in this paper a formal definition for BPEL fragments. In this paper we first study the related work on process fragments and distinguish BPEL fragments from existing reuse approaches in service-oriented process modeling. Based on the requirement analysis we present a definition of BPEL fragments in XML schema. By adopting our definition of BPEL fragments, the flexibility of modularized reuse of BPEL process models can be significantly increased.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-21&engl=1}
}
@inproceedings {INPROC-2009-20,
   author = {Ralph Mietzner and Andreas Metzger and Frank Leymann and Klaus Pohl},
   title = {{Variability Modeling to Support Customization and Deployment of Multi-Tenant-Aware Software as a Service Applications}},
   booktitle = {Proceedings of ICSE 2009 Workshop - Principles of Engineering Service Oriented Systems (PESOS)},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {18--25},
   type = {Workshop Paper},
   month = {May},
   year = {2009},
   keywords = {Software as a Service, SaaS, Variability Modelling, Provisioning, Deployment},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   contact = {mietzner@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {More and more companies are offering their software by following the Software as a Service (SaaS) model. The promise of the SaaS model is to exploit economies of scale on the provider side by hosting multiple customers (or tenants) on the same hardware and software infrastructure. However, to attract a significant number of tenants, SaaS applications have to be customizable to fulfill the varying functional and quality requirements of individual tenants. In this paper, we describe how variability modeling techniques from software product line engineering can support SaaS providers in managing the variability of SaaS applications and their requirements. Specifically, we propose using explicit variability models to systematically derive customization and deployment information for individual SaaS tenants. We also demonstrate how variability models could be used to systematically consider information about already deployed SaaS applications for efficiently deploying SaaS applications for new tenants. We illustrate our approach by a running example for a meeting planning application.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-20&engl=1}
}
@inproceedings {INPROC-2009-19,
   author = {Olha Danylevych and Dimka Karastoyanova and Frank Leymann},
   title = {{Optimal Stratification of Transactions}},
   booktitle = {ICIW 2009},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {May},
   year = {2009},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {www.iaria.org/conferences2009/ICIW09.html},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The performance of a system (implementing business processes) is directly influenced by the way its operations are split into transactions. Stratified transactions a produced by the stratification approach presented in this paper and is a way to manage a global transaction by combining the transactions coordinated using the tho-phase commit protocol (2PC) and queued transactions. In the presented stratification approach the sub-transactions are partitioned into the so-called strata which employ 2PC for transaction coordination, and the strata communicate via persistent queues. This paper investigates the mechanisms for building an optimally stratified transaction regarding certain evaluation criteria. We investigate the applicability of algorithms for local search like the hillclimbing and simulated annealing for transaction stratification, and introduce a hybrid method combining both approaches to tackle its disadvantage. We also used the population-based optimization approach (evolutionary programming). We produce recommendations for use of all the approaches depending on the optimization criteria. The approach can be applied for fragmenting workflow-based service compositions in an optimal manner and thus support the out-sourcing and insourcing scenarios.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-19&engl=1}
}
@inproceedings {INPROC-2009-18,
   author = {Branimir Wetzstein and Olha Danylevych and Frank Leymann and Marina Bitsaki and Christos Nikolaou and Willem-Jan van den Heuvel and Mike Papazoglou},
   title = {{Towards Monitoring of Key Performance Indicators Across Partners in Service Networks}},
   booktitle = {ServiceWave, MONA+},
   publisher = {Springer Berlin Heidelberg},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Workshop Paper},
   month = {February},
   year = {2009},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://www.s-cube-network.eu/MONA},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In an ever increasing dynamic environment, companies are forced to cooperate in order to meet customer needs efectively. They set up Service Networks (SN) trying to create a win-win situation for all participants of the network. The calculation of value in an SN is based on key performance indicators (KPIs) which measure the performance of underlying cross-organizational business processes. As for the calculation of KPIs of these processes monitoring information from several paricipants is needed, in an SN it is no more suficient for the participants to monitor just KPIs of their internal processes, e.g., by using Business Activity Monitoring technology. The participants now have to provide a set of monitoring events to the other partners in the SN. In this paper, we describe an approach to monitoring of KPIs across partners in a service network. An SN is mapped to a service choreography and a monitoring agreement is created which specifes how KPIs are decomposed to events that participants in the choreography have to provide. We present our approach based on a case study from the telecommunications domain.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-18&engl=1}
}
@inproceedings {INPROC-2009-15,
   author = {Marina Bitsaki and Olha Danylevych and Willem-Jan van den Heuvel and George D. Koutras and Frank Leymann and Michele Mancioppi and Christos N. Nikolaou and Mike P. Papazoglou},
   title = {{Model Transformations to Leverage Service Networks}},
   booktitle = {ICSOC workshop proceedings, WESOA 2008},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Workshop Paper},
   month = {March},
   year = {2009},
   keywords = {service networks, SOC, BPMN, business process managemen},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The Internet has catered for the transformation of traditional “stovepiped” service companies into global service networks fostering co-production of value to more effectively and efficiently satisfy the ever-growing demands of mundane customers. The catalyst of this change is the happenstance of Service Oriented Computing, providing a natural distributed computing technology paradigm for implementing and evolving such highly distributed networks of autonomous trading partners with coordinate and cooperative actions. However, how to faithfully (re-)map service networks, including value flows and inter-party interactions, to business processes and service realizations and vice-versa is still partly terra incognita. In this paper, we introduce a semi-automatic model transformation approach for creating the abstract business processes that take place between trading partners from models representing the service networks, assuming extremely limited human-involvement focused on selecting reusable transformation patterns. This approach is explored and validated using a realistic case study reflecting best practices in the telecommunications industry.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-15&engl=1}
}
@inproceedings {INPROC-2009-140,
   author = {Rania Khalaf and Dieter Roller and Frank Leymann},
   title = {{Revisiting the Behavior of Fault and Compensation Handlers in WS-BPEL}},
   booktitle = {OTM '09: Proceedings of the Confederated International Conferences, CoopIS, DOA, IS, and ODBASE 2009 on On the Move to Meaningful Internet Systems},
   publisher = {Springer-Verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {286--303},
   type = {Conference Paper},
   month = {November},
   year = {2009},
   doi = {10.1007/978-3-642-05148-7_20},
   isbn = {978-3-642-05147-0},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {When automating work, it is often desirable to compensate completed work by undoing the work done by one or more activities. In the context of workflow, where compensation actions are defined on nested 'scopes' that group activities, this requires a model of nested compensation---based transactions. The model must enable the automatic determination of compensation order by considering not only the nesting of scopes but also the control dependencies between them. The current standard for Web services workflows, Business Process Execution Language for Web Services (WS-BPEL), has such compensation capabilities. In this paper, we show that the current mechanism in WS-BPEL shows compensation processing anomalies, such as neglecting control link dependencies between nested non-isolated scopes. We then propose an alternate approach that through elimination of default handlers as well as the complete elimination of termination handlers not only removes those anomalies but also relaxes current WS-BPEL restrictions on control links. The result is a new and deterministic model for handling default compensation for scopes in structures where: (1) both fault handling and compensation handling are present and (2) the relationships between scopes include both structured nesting and graph---based links.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-140&engl=1}
}
@inproceedings {INPROC-2009-14,
   author = {Andreas Gehlert and Julia Hielscher and Olha Danylevych and Dimka Karastoyanova},
   title = {{Online Testing, Requirements Engineering and Service Faults as Drivers for Adapting Service Compositions}},
   booktitle = {ServiceWave 2008, MONA+},
   publisher = {Springer Berlin Heidelberg},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Workshop Paper},
   month = {February},
   year = {2009},
   keywords = {Service Composition, Adaptability, Requirements Engineering, Online Testing, Self-optimization, Web Services},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://www.s-cube-network.eu/MONA},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Adaptability is a key feature of service-based applications (SBAs). Multiple approaches for adaptability, including those borrowed from the tradi-tional workflow technology, can be used to react to various types of changes in the SBA’s environment. Unlike previous fragmented research, we aim at pre-senting a unified view reflecting the convergence of approaches from require-ments engineering, online testing and adaptation mechanisms for service com-positions. The main result of our approach is that a dynamic binding strategy known from service composition research leads to an interaction of the re-quirements engineering and online testing activities with an enterprise service registry only and, therefore, to a loose coupling between the three activities.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-14&engl=1}
}
@inproceedings {INPROC-2009-10,
   author = {Stephan Urbanski and Eduard Huber and Matthias Wieland and Frank Leymann and Daniela Nicklas},
   title = {{PerFlows for the Computers of the 21st Century}},
   booktitle = {Proceedings of the Seventh Annual IEEE Conference on Pervasive Computing and Communications : PerCom'09 Workshops, in 5th IEEE PerCom Workshop on Context Modeling and Reasoning; Galveston, 17.-21. March 2009},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   pages = {1--6},
   type = {Workshop Paper},
   month = {March},
   year = {2009},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In 1995, Mark Weiser introduced a scenario about the future life, where everyday objects are equipped with smart functions and the environment helps us to fulfill our everyday tasks. This paper shows how Weiser’s scenario can be realized by today’s available technologies. We combine PerFlows (to model the flow of daily tasks) and the Nexus context provisioning platform (to model and provide necessary context information to applications and devices). Furthermore, we present SmartGPS, which is able to provide fused location information even if the device is disconnected.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-10&engl=1}
}
@inproceedings {INPROC-2009-09,
   author = {Matthias Wieland and Daniel Martin and Oliver Kopp and Frank Leymann},
   title = {{SOEDA: A Methodology for Specification and Implementation of Applications on a Service-Oriented Event-Driven Architecture}},
   booktitle = {Proceedings of the 12th International Conference on Business Information Systems (BIS 2009). Poznan, Poland April 27-29, 2009.},
   editor = {Witold Abramowicz},
   address = {Poznan, Poland},
   publisher = {Springer Verlag},
   institution = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   series = {Lecture Notes in Business Information Processing},
   volume = {21},
   pages = {193--204},
   type = {Conference Paper},
   month = {April},
   year = {2009},
   doi = {10.1007/978-3-642-01190-0_17},
   keywords = {epk; epc; transformation; bpel; soa; eda; event driven architecture; cep; complex event processing},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Both Event-Driven Architecture (EDA) and Service-Oriented Architecture (SOA) are unique architectural styles widely used in today's industries. Mostly however, they exist as isolated systems that could greatly benefit from each other when being combined. This paper introduces SOEDA, an approach that unifies EDA and SOA by introducing a step-based development method taking advantage of the unique properties of each architecture. Individual steps reach from abstract process specification over event and process implementation to the the final execution phase -- described in a abstract manner and by means of an example. Resulting applications are based on state-of-the-art workflow technology using events to trigger execution of individual business activities.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-09&engl=1}
}
@inproceedings {INPROC-2009-07,
   author = {Ralph Lange and Nazario Cipriani and Lars Geiger and Matthias Gro{\ss}mann and Harald Weinschrott and Andreas Brodt and Matthias Wieland and Stamatia Rizou and Kurt Rothermel},
   title = {{Making the World Wide Space Happen: New Challenges for the Nexus Context Platform}},
   booktitle = {Proceedings of the 7th Annual IEEE International Conference on Pervasive Computing and Communications (PerCom '09). Galveston, TX, USA. March 2009},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   pages = {1--4},
   type = {Conference Paper},
   month = {March},
   year = {2009},
   keywords = {Nexus; context; mobile context-aware applications; context-awareness; context management; World Wide Space; stream-processing; situation recognition; reasoning; workflows; quality of context},
   language = {English},
   cr-category = {H.2.8 Database Applications,     H.3.4 Information Storage and Retrieval Systems and Software,     H.3.5 Online Information Services},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2009-07/INPROC-2009-07.pdf,     http://www.nexus.uni-stuttgart.de/,     http://dx.doi.org/10.1109/PERCOM.2009.4912782},
   contact = {ralph.lange@ipvs.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems;     University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems},
   abstract = {Context-aware applications rely on models of the physical world. Within the Nexus project, we envision a World Wide Space which provides the conceptual and technological framework for integrating and sharing such context models in an open, global platform of context providers. In our ongoing research we tackle important challenges in such a platform including distributed processing of streamed context data, situation recognition by distributed reasoning, efficient management of context data histories, and quality of context information. In this paper we discuss our approach to cope with these challenges and present an extended Nexus architecture.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-07&engl=1}
}
@inproceedings {INPROC-2009-05,
   author = {Daniel Wutke and Daniel Martin and Frank Leymann},
   title = {{Tuplespace-based Infrastructure for Decentralized Enactment of BPEL Processes}},
   booktitle = {Proceedings of 9. Internationale Tagung Wirtschaftsinformatik: Business Services, Konzepte, Technologien, Anwendungen (WI 2009), Vienna, Austria, February 25 - 27, 2009},
   address = {Vienna, Austria},
   publisher = {OCG},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--10},
   type = {Conference Paper},
   month = {February},
   year = {2009},
   keywords = {tuplespace; bpel; decentralized workflow enactment; ewfn; architecture},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Business processes -- expressed in the Web Service Business Process Execution Language (WS-BPEL or BPEL for short) -- are a manifestation of the two-level-programming paradigm where individual, remote-accessible Web services are composed to potentially complex orchestrations. BPEL processes are executed by so-called Workflow Management Systems that navigate through the process' activities according to the order imposed by the process model and interact with the services orchestrated by the process. While Web service technology enables interactions with remote services, process navigation is done in a centralized manner. Especially in scenarios of complex interactions between multiple distributed process participants, this way of enacting process models has several drawbacks. In the paper, we outline those drawbacks and propose an alternative approach to execution of BPEL processes in a distributed, decentralized manner. We present an overview of the system model and architecture and describe how the proposed approach enables a broad spectrum of process distribution.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-05&engl=1}
}
@inproceedings {INPROC-2009-02,
   author = {Thorsten Scheibler and Dimka Karastoyanova and Frank Leymann},
   title = {{Dynamic Message Routing Using Processes}},
   booktitle = {Proceedings of 16th Fachtagung Kommunikation in Verteilten Systemen (KiVS 09)},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {March},
   year = {2009},
   keywords = {SOAP, Routing, BPEL, ESB, SOA},
   language = {English},
   cr-category = {D.2.2 Software Engineering Design Tools and Techniques,     D.2.11 Software Engineering Software Architectures,     D.2.13 Software Engineering Reusable Software},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The Enterprise Service Bus (ESB) is composable middleware that provides applications with services such as message routing and transformation, service compositions, dynamic discovery, transactional support, coordination, security features, and others. In an ESB supporting SOAP message exchange routing algorithms typically follow the sequential SOAP message processing model, where SOAP headers are the main artefacts used to specify the message route and the processing of the payload by intermediaries along that route. This model supports neither alternative nor parallel message routes. In the case of a failing intermediary node this leads to a failure in the message delivery. Moreover, the execution order of services on SOAP message payloads at the intermediaries cannot be prescribed. In this paper, we demonstrate how the deficiencies of the SOAP message processing model can be addressed. We introduce an approach that allows for specifying SOAP message routing logic in terms of BPEL processes. We show that parallel and alternative routes for SOAP messages can be modelled and executed, and the order of services that process a message at intermediaries can be predefined to accommodate the correct processing sequence, as required by the concrete application domain. Features like dynamic discovery of services and flexible service composition are leveraged to enable flexible SOAP message routing.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-02&engl=1}
}
@inproceedings {INPROC-2009-01,
   author = {Thorsten Scheibler and Frank Leymann},
   title = {{From Modelling to Execution of Enterprise Integration Scenarios: the GENIUS tool}},
   booktitle = {Proceedings of 16th Fachtagung Kommunikation in Verteilten Systemen (KiVS 09)},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {March},
   year = {2009},
   keywords = {EAI Patterns, Integration Patterns, MDD, Parameterization, Modelling},
   language = {English},
   cr-category = {D.2.2 Software Engineering Design Tools and Techniques,     D.2.11 Software Engineering Software Architectures,     D.2.13 Software Engineering Reusable Software},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {One of the predominant problems IT companies are facing today is Enterprise Application Integration (EAI). Most of the infrastructures built to tackle integration issues are proprietary because no standards exist for how to model, develop, and actually execute integration scenarios. EAI patterns gain importance for non-technical business users to ease and harmonize the development of EAI scenarios. These patterns describe recurring EAI challenges and propose possible solutions in an abstract way. Therefore, one can use those patterns to describe enterprise architectures in a technology neutral manner. However, patterns are documentation only used by developers and systems architects to decide how to manually implement an integration scenario. Thus, patterns are not theoretical thought to stand for artefacts that will immediately be executed. This paper presents a tool supporting a method how EAI patterns can be used to automatically generate executable artefacts for various target platforms using a model-driven development approach, hence turning patterns into something executable. Therefore, we introduce a continuous tool chain beginning at the design phase and ending in executing an integration solution in a fully automatically manner. For evaluation purposes we introduce a scenario demonstrating how the tool is utilized for modelling and actually executing an integration scenario.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2009-01&engl=1}
}
@inproceedings {INPROC-2008-99,
   author = {Jussi Vanhatalo and Hagen V{\"o}lzer and Frank Leymann and Simon Moser},
   title = {{Automatic Workflow Graph Refactoring and Completion}},
   booktitle = {ICSOC 2008},
   editor = {A. Bouguettaya and I. Krueger and T. Margaria},
   publisher = {Springer-Verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science},
   volume = {5364},
   pages = {100--115},
   type = {Conference Paper},
   month = {November},
   year = {2008},
   language = {English},
   cr-category = {H.4.1 Office Automation,     D.3 Programming Languages},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Workflow graphs are used to model the control flow of business processes in various languages, e.g., BPMN, EPCs and UML activity diagrams. We present techniques for automatic workflow graph refactoring and completion. These techniques enable various use cases in modeling and runtime optimization. For example they allow us to complete a partial workflow graph, they provide local termination detection for workflow graphs with multiple ends, and they allow us to execute models containing OR-joins faster. Some of our techniques are based on workflow graph parsing and the Refined Process Structure Tree},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-99&engl=1}
}
@inproceedings {INPROC-2008-93,
   author = {Tobias Unger and Stephanie Mauchart and Frank Leymann and Thorsten Scheibler},
   title = {{Aggregation of Service Level Agreements in the Context of Business Processes}},
   booktitle = {Proceedings of the Twelfth IEEE Enterprise Distributed Object Conference (EDOC 2008), 15-19 September 2008, Munich, Bavaria, Germany},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {43--52},
   type = {Conference Paper},
   month = {September},
   year = {2008},
   isbn = {978-0-7695-3373-5},
   doi = {10.1109/EDOC.2008.29},
   keywords = {Service Level Agreements; Business Processes; BPEL; Aggregation},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://ieeexplore.ieee.org/search/wrapper.jsp?arnumber=4634756},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {One can observe that more and more companies are focusing on their core compenetency and are outsourcing parts or even complete business processes to service providers. Service Level Agreements (SLAs) are used as a contractual basis to define certain non-functional properties (e.g. response time) a service has to provide. To determine the SLA of a business process a priori, the SLAs of the invoked services need to be aggregated into a single SLA for the business process. This paper defines a method how a service provider can aggregate the SLAs of the individual services within a business process into a single SLA. This provides a service provider with the capability to annotate the service that the business process implements with an appropriate SLA. We propose a framework that helps in carrying out the SLA aggregation within business processes. The framework consists of two parts: (i) a formal model for SLAs and (ii) a concept to aggregate SLAs, where algorithms can be plugged in.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-93&engl=1}
}
@inproceedings {INPROC-2008-92,
   author = {Oliver Kopp and Daniel Martin and Daniel Wutke and Frank Leymann},
   title = {{On the Choice Between Graph-Based and Block-Structured Business Process Modeling Languages}},
   booktitle = {Modellierung betrieblicher Informationssysteme (MobIS 2008). Saarbr{\"u}cken, Germany, November 27 - 28, 2008.},
   publisher = {Gesellschaft f{\"u}r Informatik e.V. (GI)},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Informatics},
   volume = {P-141},
   pages = {59--72},
   type = {Conference Paper},
   month = {November},
   year = {2008},
   issn = {1617-5468},
   isbn = {978-3-88579-235-2},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://www.gi-ev.de/service/publikationen/lni/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The most prominent business process notations in use today are BPMN, EPC and BPEL. While all those languages show similarities on the conceptual level and share similar constructs, the semantics of these constructs and even the intended use of the language itself are often quite different. As a result, users are uncertain when to use which language or construct in a particular language, especially when they have used another business process notation before. Specifically problematic are the semantics of join and loop constructs that have also been heavily discussed in literature. In this paper, we discuss the core characteristics of graph-based and block-structured modeling languages and compare them with respect to their join and loop semantics.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-92&engl=1}
}
@inproceedings {INPROC-2008-89,
   author = {Daniel Martin and David de Francisco and Reto Krummenacher and Hans Moritsch and Daniel Wutke},
   title = {{An Architecture for a QoS-Aware Application Integration Middleware}},
   booktitle = {Proceedings of the 11th International Conference on Business Information Systems (BIS 2008). Innsbruck, Austria, 5-7 May 2008.},
   editor = {Witold Abramowicz and Dieter Fensel},
   publisher = {Springer Berlin Heidelberg},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {333--344},
   type = {Conference Paper},
   month = {May},
   year = {2008},
   doi = {10.1007/978-3-540-79396-0_29},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,     C.4 Performance of Systems,     H.2.4 Database Management Systems},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Complex application integration scenarios often demand for different combinations of qualities of services (QoS) at middleware level. The scenario presented in the paper, for instance, requires transactional middleware behaviour for business negotiations between a relatively small number of participants on the one hand, while on the other hand it requires high scalability for distributing data to a large number of clients. The concept of Triple Space, a semantically enhanced, distributed tuplespace middleware based on an extended Linda model, has been developed to provide such an infrastructure. In contrast to existing middleware infrastructures, Triple Space supports a set of configurations which define the system’s QoS. In this paper, we present a motivating use case scenario, deduce requirements for the architecture of Triple Space, define its architecture and three QoS configurations, and outline our approach towards implementing a highly scalable distributed communication infrastructure.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-89&engl=1}
}
@inproceedings {INPROC-2008-88,
   author = {Omair Shafiq and Francois Scharffe and Daniel Wutke and German Toro del Valle},
   title = {{Resolving Data Heterogeneity Issues in Open Distributed Communication Middleware}},
   booktitle = {Proceedings of the 2008 Third International Conference on Internet and Web Applications and Services (ICIW2008)},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {494--499},
   type = {Conference Paper},
   month = {July},
   year = {2008},
   doi = {10.1109/ICIW.2008.71},
   language = {English},
   cr-category = {H.2.4 Database Management Systems},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Triple Space Computing is a communication and coordination paradigm that allows communication of semantic technologies in general, by publish and read of semantic data. It has also been provided as an underline communication middleware for Semantic Web Services. While focusing on scalability and openness of Triple Space Computing to bring it into its full potential in a global view, the possibility of heterogeneity among different users communicating over Triple Space is very likely to arise. This paper focuses on providing the Triple Space Computing with data mediation to enable easy integration of data, information, and knowledge. Mediation is a technique to overcome heterogeneity issues in a system, i.e. to remove differences in the syntactic representation and the intended semantics of data that is exchanged [2]. The paper introduces an Abstract Mapping Language and shows how mapping rules can be created using this mapping language. It further proposes mediation APIs for users and internal system. It also explains the grounding of mediation mapping rules to Triple Space. It further provides a refined version of architecture of the mediation engine along with its bindings with other components of Triple Space Computing paradigm.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-88&engl=1}
}
@inproceedings {INPROC-2008-87,
   author = {Daniel Wutke and Daniel Martin and Frank Leymann},
   title = {{Model and Infrastructure for Decentralized Workflow Enactment}},
   booktitle = {Proceedings of the 2008 ACM Symposium on Applied Computing (ACM SAC 08). Fortaleza, Brasil, March 16 - 20, 2008},
   address = {Fortaleza, Brasil},
   publisher = {ACM},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {90--94},
   type = {Conference Paper},
   month = {March},
   year = {2008},
   doi = {10.1145/1363686.1363712},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Today, enactment of Web service flows – the process of evaluating control flow and executing activities a workflow is composed of – is typically done by a centralized workflow enactment service as part of a Workflow management system. This exhibits a number of drawbacks with regard to process adaptability and process fragmentation among a number of participating partners. In order to overcome the deficiencies of centralized process navigation, we propose a model for flexible and adaptable distributed processes as orchestrations of a set of self-coordinating components, without the need for central coordination. Furthermore, we provide key characteristics and an architecture for the development of a supporting infrastructure that facilitates both, deployment and management of distributed components as well as decentralized workflow enactment.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-87&engl=1}
}
@inproceedings {INPROC-2008-85,
   author = {Tammo van Lessen and Frank Leymann and Ralph Mietzner and J{\"o}rg Nitzsche and Daniel Schleicher},
   title = {{A Management Framework for WS-BPEL}},
   booktitle = {Proceedings of the 6th IEEE European Conference on Web Services 2008},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {187--196},
   type = {Conference Paper},
   month = {November},
   year = {2008},
   keywords = {WS-BPEL; BPEL; Management; Monitoring; Resources; WS-RF; REST; JMX},
   language = {English},
   cr-category = {H.4.1 Office Automation,     K.1 The Computer Industry},
   ee = {http://www.computing.dcu.ie/ecows08/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {WS-BPEL is the standard to define executable business processes in a Web service world. Numerous commercial and open source BPEL engines exist on the market today that allow the execution of process models defined in BPEL. However, these execution engines only provide access to process model and process instance data in terms of proprietary APIs. In this paper we present an approach that models BPEL process models and process instances as resources and thus provides a uniform access scheme for process model and process instance data. This is crucial because access to process model and process instance data is needed in different scenarios that are of key relevance in enterprises today. These scenarios include compliance checking, repair of faulted business processes as well as real-time monitoring of business processes. The lack of a uniform access scheme to process model and process instance data hampers the exchangeability of BPEL engines and therefore results in a potential vendor lock-in.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-85&engl=1}
}
@inproceedings {INPROC-2008-74,
   author = {K. Mokhtari and S. Benbernou and M. Said and E. Coquery and M.S. Hacid and Frank Leymann},
   title = {{Verification of Privacy Timed Properties in Web Service Protocols}},
   booktitle = {Proceedings of the International Conference on Services Computing, SCC 2008},
   publisher = {IEEE Computer Society Press},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {593--594},
   type = {Conference Paper},
   month = {July},
   year = {2008},
   doi = {10.1109/SCC.2008.154},
   isbn = {978-0-7695-3283-7},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In this work we propose an approach for verifying privace timed-related prroperties of web service protocols. While in our previous work the addressed problem in business protocols is focused on the analysis and management of functional requirements that support rich timing constraints, our approach extends the previous results to capture the timed behavior of privacy constraints. Hence, we provide a model called Timed Private Business Protocol TPBP. Next, we emphasize the timed properties related to privacy in TPBP. Finally, we present the different types of timed property verification to achieve upon the timed private business protocol.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-74&engl=1}
}
@inproceedings {INPROC-2008-72,
   author = {Oliver Kopp and Branimir Wetzstein and Ralph Mietzner and Stefan Pottinger and Dimka Karastoyanova and Frank Leymann},
   title = {{A Model-Driven Approach to Implementing Coordination Protocols in BPEL}},
   booktitle = {1st International Workshop on Model-Driven Engineering for Business Process Management (MDE4BPM 2008)},
   publisher = {Springer-Verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Business Information Processing},
   volume = {17},
   pages = {188--199},
   type = {Workshop Paper},
   month = {September},
   year = {2008},
   doi = {10.1007/978-3-642-00328-8_19},
   keywords = {MDA; BPEL; WS-Coordination; WS-Business Activity},
   language = {English},
   cr-category = {H.4.1 Office Automation,     K.4.4 Electronic Commerce},
   ee = {http://www.inf.unisi.ch/mde4bpm08/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {WS-Coordination defines a framework for establishing pro- tocols for coordinating the outcome agreement within distributed ap- plications. The framework is extensible and allows support for multiple coordination protocols. To facilitate the realization of new coordination protocols we present a model-driven approach for the generation of BPEL processes used as implementation of coordination protocols. We show how coordination protocols can be modeled in domain-specific graph-based diagrams and how to transform such graphs into abstract BPEL process models representing the behavior of the coordinator and the participants in the protocol.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-72&engl=1}
}
@inproceedings {INPROC-2008-71,
   author = {Niels Lohmann and Oliver Kopp},
   title = {{Tools4BPEL4Chor}},
   booktitle = {YR-SOC 2008},
   publisher = {online},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {74--75},
   type = {Workshop Paper},
   month = {June},
   year = {2008},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2008-71/INPROC-2008-71.pdf,     http://www.yrsoc.org},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In this paper, we present several tools support the modeling, analysis, synthesis, and correction of BPEL4Chor choreographies},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-71&engl=1}
}
@inproceedings {INPROC-2008-64,
   author = {Daniel Wutke and Daniel Martin and Frank Leymann},
   title = {{Facilitating Complex Web Service Interactions through a Tuplespace Binding}},
   booktitle = {Proceedings of Distributed Applications and Interoperable Systems, 8th IFIP WG 6.1 International Conference, DAIS 2008, Oslo, Norway, June 4-6, 2008.},
   editor = {Rene Meier and Sotirios Terzis},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {275--280},
   type = {Conference Paper},
   month = {June},
   year = {2008},
   doi = {10.1007/978-3-540-68642-2_22},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The SOAP messaging framework, as one key technology of the Web service technology standard stack, de nes a standardized message format for Web service interactions, a set of rules governing their processing and a mechanism that describes how SOAP messages can be transmitted over di erent network transport protocols, called SOAP bindings. The most prominent example for a Web service transport today, is the Hypertext Transfer Protocol (HTTP), which however su ers from certain drawbacks such as being inherently synchronous in nature and not providing decoupling of message sender and receiver in reference or time. In this paper, we present tuplespace technology as an alternative Web service transport that is characterized by a number of properties that are not found in current Web service transports: asynchronism, strong decoupling of sender and receiver and support for advanced message exchange patterns, such as one-to-many interactions, directly on the transport level. We describe the representation of SOAP messages in tuple form and exemplify how to use the operations provided by the tuplespace interface to realize certain Web service message exchange patterns.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-64&engl=1}
}
@inproceedings {INPROC-2008-60,
   author = {Zhilei Ma and Frank Leymann},
   title = {{A Lifecycle Model for Using Process Fragment in Business Process Modeling}},
   booktitle = {Proceedings of the 9th Workshop on Business Process Modeling, Development, and Support (BPDMS 2008)in conjunctin with The 20th International Conference on Advanced Information Systems Engineering (CAiSE'08), Montpellier, France, 16-18 June, 2008},
   address = {Montpellier},
   publisher = {Online},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--9},
   type = {Workshop Paper},
   month = {June},
   year = {2008},
   keywords = {process fragment, business process modeling, business process management, bpm, lifecycle, reuse},
   language = {English},
   cr-category = {H.1 Models and Principles},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Business organizations strive to increase the quality of their business processes and the productivity in modeling the business processes. Reuse of process modeling artifacts can contribute to achieving this goal. In this paper, we propose a lifecycle model for reusing process fragment in business process modeling, which (i) guides the business user in understanding and adopting the concepts of using process fragment in business process modeling; (ii) guides the development of business process modeling tool and business process repository that support reusing process fragment in business process modeling.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-60&engl=1}
}
@inproceedings {INPROC-2008-47,
   author = {Carlos Pedrinaci and Christian Brelage and Tammo van Lessen and John Domingue and Dimka Karastoyanova and Frank Leymann},
   title = {{Semantic Business Process Management: Scaling up the Management of Business Processes}},
   booktitle = {Proceedings of the 2nd IEEE International Conference on Semantic Computing (ICSC) 2008},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {546--553},
   type = {Conference Paper},
   month = {August},
   year = {2008},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Business Process Management (BPM) aims at supporting the whole life-cycle necessary to deploy and maintain business processes in organisations. Despite its success however, BPM suffers from a lack of automation that would support a smooth transition between the business world and the IT world. We argue that Semantic BPM, that is, the enhancement of BPM with Semantic Web Services technologies, provides further scalability to BPM by increasing the level of automation that can be achieved. We describe the particular SBPM approach developed within the SUPER project and we illustrate how it contributes to enhancing existing BPM solutions in order to achieve more flexible, dynamic and manageable business processes.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-47&engl=1}
}
@inproceedings {INPROC-2008-44,
   author = {J{\"o}rg Nitzsche and Tammo van Lessen and Frank Leymann},
   title = {{Extending BPEL light for Expressing Multi-Partner Message Exchange Patterns}},
   booktitle = {Proceedings of the 12th IEEE International EDOC Conference (EDOC 2008)},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {245--254},
   type = {Conference Paper},
   month = {September},
   year = {2008},
   isbn = {978-0-7695-3373-5},
   keywords = {BPEL; BPEL light; MEP; Message Exchange Pattern; Multi-Partner},
   language = {English},
   cr-category = {H.4.1 Office Automation,     K.1 The Computer Industry},
   ee = {http://www.lrz-muenchen.de/~edoc2008/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Message exchange patterns provide means to define the message flow of a service and how these messages are related in an abstract and reusable manner. They are an integral part of WSDL 2.0 and allow defining operations that have a message exchange beyond requestresponse. They reduce the impedance mismatch between imperative programming and message orientation while emphasizing the message orientated nature of Web Services. Whereas BPEL defines a flow between Web Service operations, BPELlight is an appropriate candidate to define the flow within operations since it abstracts from WSDL. In this paper we extended BPELlight to facilitate capturing complex multi-lateral message exchanges. We refine the partner model and relax the definition of a conversation to enable modelling conversations that involve different partner types. We also extend the language with a first-class construct that enables storing, querying and thus distinguishing addressing information related to multiple partner instances. This way we enable modelling message exchange patterns that capture business logic in a reusable manner on an abstract level like for instance a request for bid scenario or a business transaction for purchase.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-44&engl=1}
}
@inproceedings {INPROC-2008-43,
   author = {Branimir Wetzstein and Zhilei Ma and Frank Leymann},
   title = {{Towards Measuring Key Performance Indicators of Semantic Business Processes}},
   booktitle = {Proceedings of 11th International Conference on Business Information Systems (BIS 2008), Innsbruck, Austria, 5-7 May 2008.},
   editor = {Witold Abramowicz and Dieter Fensel},
   address = {Berlin, Heidelberg},
   publisher = {Springer-Verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {227--238},
   type = {Conference Paper},
   month = {May},
   year = {2008},
   keywords = {semantic business process management, sbpm, performance management, process performance metrics, key performance indicator, kpi},
   language = {English},
   cr-category = {H.4 Information Systems Applications},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Business Activity Monitoring (BAM) enables continuous, real-time performance measurement of business processes based on key performance indicators (KPI). The performance information is employed by business users but prior support from IT engineers is required for setting up the BAM solution. Semantic Business Process Management (SBPM) tries to minimize the needed support from IT staff throughout the business process lifecycle. In this paper we introduce a framework for BAM as part of SBPM. We show how performance measurement related activities can be integrated into the semantic business process lifecycle. KPIs are modeled by business analysts exploiting semantic annotations of business processes. KPI models are automatically transformed to IT-level event-based models and used for real-time monitoring using reasoning technology.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-43&engl=1}
}
@inproceedings {INPROC-2008-42,
   author = {Ralph Mietzner and Frank Leymann},
   title = {{Towards Provisioning the Cloud: On the Usage of Multi-Granularity Flows and Services to Realize a Unified Provisioning Infrastructure for SaaS Applications}},
   booktitle = {Proceedings of the International Congress on Services, SERVICES 2008},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {July},
   year = {2008},
   keywords = {Cloud Computing; SaaS; on Demand; Provisioning},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The automatic provisioning of applications is an importent task for the success of Software as a Service (SaaS) providers. Different provisioning engines from different vendors and open source projects with different interfaces have been emerging lately. Additionally, infrastructure providers that provide infrastructure on demand now provide computing resources that can be integrated in a SaaS provider’s computing environment. In order to allow SaaS application providers to specify generic installation and maintenance flows independent from the underlying provisioning engines we propose an architecture for a generic provisioning infrastructure based on Web services and workflow technology.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-42&engl=1}
}
@inproceedings {INPROC-2008-41,
   author = {Ralph Mietzner and Frank Leymann},
   title = {{Generation of BPEL Customization Processes for SaaS Applications from Variability Descriptors}},
   booktitle = {Proceedings of the International Conference on Services Computing, Industry Track, SCC 2008},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {July},
   year = {2008},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Software as a Service (SaaS) is a new delivery model for software. Software in a SaaS model is no longer run exclusively for one customer at a customer’s premise but run at a service provider and accessed via the Internet. A provider of Software as a Service exploits economies of scale by hosting and providing the same application for several different customers. However, each individual customer has different requirements for the same basic application. In order to allow each customer to customize the process layer and related artifacts of a SaaS application to their specific needs the application needs to provide a set of variability points that can be modified by customers. In this paper we describe the notion of a variability descriptor that defines variability points for the process layer and related artifacts of process-based, service-oriented SaaS applications. Furthermore we describe how these variability descriptors can be transformed into a WS-BPEL process model that can then be used to guide a customer through the customization of the SaaS application.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-41&engl=1}
}
@inproceedings {INPROC-2008-40,
   author = {Ralph Mietzner and Frank Leymann and Mike P. Papazoglou},
   title = {{Defining Composite Configurable SaaS Application Packages Using SCA, Variability Descriptors and SaaS Multi-Tenancy Patterns}},
   booktitle = {Proceedings of the 3rd Intl. Conf. on Internet and Web Applications and Services ICIW 2008},
   address = {Athens, Greece},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {January},
   year = {2008},
   keywords = {SaaS; SCA; Multi-Tenancy; SOA},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Currently, several vendors and projects are building proprietary SaaS platforms where more and more applications are hosted in a Software as a Service business model. However, these proprietary platforms prevent that applications offered by different SaaS application vendors can be easily reused on the platforms offered by the different SaaS hosting providers. In this paper we describe a package format for composite configurable SaaS application packages for applications developed following a service oriented architecture. We show how the service component architecture (SCA) can be extended with variability descriptors and SaaS multi-tenancy patterns to package and deploy multitenant aware configurable composite SaaS applications.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-40&engl=1}
}
@inproceedings {INPROC-2008-38,
   author = {Oliver Kopp and Tammo van Lessen and J{\"o}rg Nitzsche},
   title = {{The Need for a Choreography-aware Service Bus}},
   booktitle = {YR-SOC 2008},
   publisher = {Online},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {28--34},
   type = {Workshop Paper},
   month = {June},
   year = {2008},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2008-38/INPROC-2008-38.pdf,     http://www.yrsoc.org},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Choreographies offer means to describe the long-running collaboration of business partners. Such descriptions can be used to create new participant processes which comply to the overall choreography or to check whether participating processes conform to the protocol. In addition, choreography descriptions allow for asserting whether a completed cross-organizational conversation has been compliant to the planned choreography. However, choreography descriptions have so far not been used during execution but only during design time. Therefore, it is not yet possible to immediately detect protocol violations and to instantly handle such violations. In this paper we motivate the need of a Choreography-aware Service Bus which is capable of tracking the soundness of cross-organizational conversations while they are running. This fosters a novel notion of exception handling in the context of choreographies.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-38&engl=1}
}
@inproceedings {INPROC-2008-34,
   author = {Tammo van Lessen and J{\"o}rg Nitzsche and Frank Leymann},
   title = {{Formalising Message Exchange Patterns using BPEL light}},
   booktitle = {Proceedings of the 5th International Conference on Services Computing (SCC'08) Research Track},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {353--360},
   type = {Conference Paper},
   month = {July},
   year = {2008},
   language = {English},
   cr-category = {H.4.1 Office Automation,     K.1 The Computer Industry},
   ee = {http://conferences.computer.org/scc/2008/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {In a message-driven SOA, message exchange patterns (MEPs) define a reusable notion of conversational contracts between a service consumer and a service provider from the provider's point of view. They enable a common understanding regarding a message flow between both parties. In contrast to version 1.1 of the Web Service Description Language (WSDL) the current version 2.0 has introduced a template for defining such patterns that allows to define and reference patterns beyond the standard input/output ones defined in the specification. Although reasonable, this approach brings several disadvantages which we point out in this paper. Since WSDL 2.0 MEPs and WS-BPEL processes describe interaction behaviour from the same perspective BPEL makes a perfect candidate as a language for formalising MEPs, especially because it provides a powerful mechanism for describing control flow and correlation of related messages. In this work we propose a way to formalising MEPs using a WSDL-less BPEL dialect called BPEL light. We introduce a new abstract BPEL profile for defining reusable and machine-readable MEPs that is capable of expressing arbitrary message exchanges. With this approach we pave the way for more flexible interaction styles and reduce the impedance mismatch between imperative programming and message orientation.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-34&engl=1}
}
@inproceedings {INPROC-2008-33,
   author = {J{\"o}rg Nitzsche and Tammo van Lessen and Frank Leymann},
   title = {{WSDL 2.0 Message Exchange Patterns: Limitations and Opportunities}},
   booktitle = {Proceedings of the 3rd International Conference on Internet and Web Applications and Services (ICIW 2008)},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {June},
   year = {2008},
   language = {English},
   cr-category = {H.4.1 Office Automation,     K.1 The Computer Industry},
   ee = {http://www.iaria.org/conferences2008/ProgramICIW08.html},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The Web Service Description Language (WSDL) provides means to describe functional aspects of a service in a Service Oriented Architecture (SOA) based on Web Service technology. In contrast to its predecessor (WSDL 1.1), WSDL 2.0 does not define a fixed set of operation types but provides for a generic mechanism to define an operation by means of message exchange patterns (MEPs). In this paper we identify new MEPs and extend the template used to define MEPs to allow expressing more complex patterns. Furthermore, we compare the expressivity of MEPs in general with other work and formalisms in the field of service interaction. We give a refined definition of MEPs based on a detailed discussion and discuss how WSDL and the MEPs in particular can be combined with the choreography approach.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-33&engl=1}
}
@inproceedings {INPROC-2008-31,
   author = {Olaf Zimmermann and Cesare Pautasso and Frank Leymann},
   title = {{RESTful Web Services vs. ``Big'' Web Services - Making the Right Architectural Decisions}},
   booktitle = {Proc. 17th International World Wide Web Conference (WWW 2008)},
   publisher = {Online},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {April},
   year = {2008},
   language = {English},
   cr-category = {K.1 The Computer Industry},
   ee = {http://www2008.org/papers/fp179.html},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Recent technology trends in the Web Services (WS) domain indicate that a solution eliminating the presumed complexity of the WS-* standards may be in sight: advocates of REpresentational State Transfer (REST) have come to believe that their ideas explaining why the World Wide Web works are just as applicable to solve enterprise application integration problems and to simplify the plumbing required to build service-oriented architectures. In this paper we objectify the WS-* vs. REST debate by giving a quantitative technical comparison based on architectural principles and decisions. We show that the two approaches differ in the number of architectural decisions that must be made and in the number of available alternatives. This discrepancy between freedom-from-choice and freedom-of-choice explains the complexity difference perceived. However, we also show that there are significant differences in the consequences of certain decisions in terms of resulting development and maintenance costs. Our comparison helps technical decision makers to assess the two integration styles and technologies more objectively and select the one that best fits their needs: REST is well suited for basic, ad hoc integration scenarios, WS-* is more flexible and addresses advanced quality of service requirements commonly occurring in enterprise computing.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-31&engl=1}
}
@inproceedings {INPROC-2008-30,
   author = {Olaf Zimmermann and Uwe Zdun and Thomas Gschwind and Frank Leymann},
   title = {{Combining Pattern Languages and Architectural Decision Models in a Comprehensive and Comprehensible Design Method}},
   booktitle = {Seventh Working IEEE/IFIP Conference on Software Architecture - WICSA 2008},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {156--166},
   type = {Conference Paper},
   month = {February},
   year = {2008},
   doi = {10.1109/WICSA.2008.19},
   language = {English},
   cr-category = {K.1 The Computer Industry},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {When constructing software systems, software architects must identify and evaluate many competing design options and document the rationale behind any selections made. Two supporting concepts are pattern languages and architectural decision models. Unfortunately, both concepts only provide partial support: Extensive upfront education is needed for practitioners to be in command of the full pattern literature relevant in their field; retrospective architectural decision modeling is viewed as a painful extra responsibility without immediate gains. In this paper, we combine pattern languages and reusable architectural decision models into a design method that is both comprehensive and comprehensible. Our design method identifies the required decisions in requirements models systematically, gives domain-specific pattern selection advice, and provides traceability from platform-independent patterns to platform-specific decisions. We validate our approach by applying it to enterprise applications as an exemplary application genre and a SOA case study from the finance industry.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-30&engl=1}
}
@inproceedings {INPROC-2008-27,
   author = {Oliver Kopp and Rania Khalaf and Frank Leymann},
   title = {{Deriving Explicit Data Links in WS-BPEL Processes}},
   booktitle = {Proceedings of the International Conference on Services Computing, SCC 2008},
   address = {Honolulu, Hawaii, USA},
   publisher = {IEEE Computer Society Press},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {367--376},
   type = {Conference Paper},
   month = {July},
   year = {2008},
   doi = {10.1109/SCC.2008.122},
   isbn = {978-0-7695-3283-7},
   keywords = {Data-flow Analysis; Reaching Definitions Analysis; def-use edges; data link; BPEL},
   language = {English},
   cr-category = {D.3 Programming Languages,     F.3.2 Semantics of Programming Languages},
   ee = {http://conferences.computer.org/scc/2008/},
   contact = {kopp@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {WS-BPEL is a standard language to model business processes. Control flow is modeled explicitly using links. Data is passed via shared variables and there is no notion of explicit data links. However, explicit data links are an important means to reason about business process models. We present an algorithm to derive explicit data links in WS-BPEL processes. By considering dead path elimination as defined in WS-BPEL, we reduce the number of derived data links when compared to existing approaches that ignore dead path elimination.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-27&engl=1}
}
@inproceedings {INPROC-2008-25,
   author = {Thorsten Scheibler and Frank Leymann},
   title = {{A Framework for Executable Enterprise Integration Patterns}},
   booktitle = {Enterprise Interoperability III: New Challenges and Industrial Approaches},
   editor = {Kai Mertins and Ruggaber Rainer and Keith Popplewell and Xiaofei Xu},
   publisher = {Springer},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {485--497},
   type = {Conference Paper},
   month = {March},
   year = {2008},
   language = {English},
   cr-category = {D.2.11 Software Engineering Software Architectures,     D.2.13 Software Engineering Reusable Software,     K.6.4 System Management},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {A great challenge for enterprises is the improvement of the utilization of their landscape of heterogeneous applications in complex EAI (Enterprise Application Integration) scenarios. Enterprise Application Integration Patterns help to address this challenge by describing recurring EAI problems and proposing possible solutions at an abstract level. However, EAI patterns are documentation only used by systems architects and developers to decide how to implement an integration solution. Thus, patterns do not specify how to produce the code that will actually implement the solution described by the pattern on a specific middleware. In this paper we introduce a framework that provides configuration capabilities for EAI patterns. The framework also allows to generate executable integration code from EAI patterns using a model-driven architecture approach. Furthermore, we present a tool providing this framework.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-25&engl=1}
}
@inproceedings {INPROC-2008-19,
   author = {Matthias Wieland and Peter Kaczmarczyk and Daniela Nicklas},
   title = {{Context Integration for Smart Workflows}},
   booktitle = {Proceedings of the Sixth Annual IEEE International Conference on Pervasive Computing and Communications},
   address = {Hong Kong},
   publisher = {IEEE computer society},
   institution = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   pages = {239--242},
   type = {Conference Paper},
   month = {March},
   year = {2008},
   isbn = {0-7695-3113-X},
   language = {English},
   cr-category = {H.4 Information Systems Applications},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The usage of workflow technology to model and execute business processes is widespread in many enterprises and within the software industry. With the growing maturity of sensors, wireless communication, and distributed computing environments, we can enhance this approach to enable smart workflows, which are business processes crossing the boundary to the physical world. Applications for such processes can be found in many application domains, like logistics or in smart factory environments. To realize smart workflows, workflow engines can be coupled with existing context provisioning systems. However, there is a gap between the rather lowlevel provisioning of context (e.g., sensor data and stock information) and the concepts needed in smart workflows (e.g., ”is a spare tool available?”). The main contribution of this paper is to bridge this gap: we show how integration processes can be used to provide context information at different semantical levels for smart workflows.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-19&engl=1}
}
@inproceedings {INPROC-2008-18,
   author = {Daniela Nicklas and Matthias Grossmann and Jorge Minguez and Mattias Wieland},
   title = {{Adding High-level Reasoning to Efficient Low-level Context Management: a Hybrid Approach}},
   booktitle = {Proceedings of the Sixth Annual IEEE Conference on Pervasive Computing and Communications : PerCom'08 Workshops, in 5th IEEE PerCom Workshop on Context Modeling and Reasoning; Hongkong, 17.-21. March 2008},
   address = {Los Alamitos - California, Washington, Tokyo},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   series = {IEEE Computer Society},
   volume = {Order Number E3113},
   pages = {447--452},
   type = {Workshop Paper},
   month = {March},
   year = {2008},
   isbn = {0-7695-3113-X},
   isbn = {978-0-7695-3113-7},
   keywords = {higher level context; pervasive computing; ubiquitous computing; context-aware applications},
   language = {English},
   cr-category = {D.1.6 Logic Programming,     D.2.11 Software Engineering Software Architectures,     H.2.8 Database Applications},
   ee = {http://www.nexus.uni-stuttgart.de/COMOREA,     http://www.nexus.uni-stuttgart.de},
   contact = {Daniela Nicklas dnicklas@acm.org},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;     University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Rule-based context reasoning is an expressive way to define situations, which are crucial for the implementation of many context-aware applications. Along the scenario of the Conference Guard application we show how this reasoning can be done both by leveraging an efficient context management (realized by the Nexus platform) and by a generic rule based service. We present the architecture of the Nexus semantic service, which uses the underlying definition of a low-level context model (the Nexus Augmented World Model) to carry out rules given in first order logic. We realize this service in a straight forward manner by using state-of-the-art software components (the Jena 2 framework) and evaluate the number of instances this approach can handle. Our first experiences show that a pre-selection of instances is necessary if the semantic service should work on a large-scale context model.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-18&engl=1}
}
@inproceedings {INPROC-2008-124,
   author = {Kia Teymourian and Lyndon Nixon and Daniel Wutke and Reto Krummenacher and Hans Moritsch},
   title = {{Implementation of a Novel Semantic Web Middleware Approach Based on Triplespaces}},
   booktitle = {Proceedings of the International Conference on Semantic Computing: ICSC 2008},
   editor = {IEEE Computer Society},
   address = {Los Alamitos, CA, USA},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {518--523},
   type = {Conference Paper},
   month = {August},
   year = {2008},
   isbn = {http://doi.ieeecomputersociety.org/10.1109/ICSC.2008.88},
   language = {English},
   cr-category = {D.4.7 Operating Systems Organization and Design},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The semantic Web and Web services have emerged as a new paradigm for knowledge-based applications, both human and machine controlled. The coordination of semantic clients or services is necessary to achieve goals only possible from the combination of knowledge based activities. Triple space computing is a new coordination paradigm based on semantics and tuplespaces which could be used for the coordination of semantic Web clients and services. Triple space computing substitutes synchronous message exchange for persistent publication of knowledge in virtual data stores called tuplespaces. A tuplespace based architecture can handle the scalability, heterogeneity and dynamism which arises in highly distributed environments. In this paper, we describe the important architectural decisions in our implementation of a semantic tuplespace based middleware. We report on our practical experiences, and the benefits and challenges of triple space computing as a new paradigm for semantic Web and Web service communication.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-124&engl=1}
}
@inproceedings {INPROC-2008-121,
   author = {Branimir Wetzstein and Dimka Karastoyanova and Frank Leymann},
   title = {{Towards Management of SLA-Aware Business Processes Based on Key Performance Indicators}},
   booktitle = {Proceedings of the 9th Workshop on Business Process Modeling, Development, and Support (BPMDS'08); Montpellier, France, June 16 – 17, 2008},
   publisher = {Online},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Workshop Paper},
   month = {June},
   year = {2008},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {It is increasingly important that Service Level Agreements (SLAs) are taken into account when business processes are exposed as services in a Service Oriented Architecture. SLAs define expected service behavior and non-functional properties of the service. The fact that the service provider has to offer certain guarantees concerning SLA properties has an impact on the business process lifecycle. In this paper we introduce a stepwise approach for management of SLA-aware service compositions based on process performance requirements specified as Key Performance Indicators. The approach is based on the process lifecycle known from Business Process Management and comprises a modeling, configuration and execution phase. We incorporate existing work on SLA modeling, QoS aggregation, and QoS-based service selection, and identify several problems specific to SLA-aware business processes.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-121&engl=1}
}
@inproceedings {INPROC-2008-120,
   author = {Marina Bitsaki and Olha Danylevych and Willem-Jan van den Heuvel and George Koutras and Frank Leymann and Michele Mancioppi and Christos Nikolaou and Mike Papazoglou},
   title = {{An Architecture for Managing the Lifecycle of Business Goals for Partners in a Service Network}},
   booktitle = {Towards a Service-Based Internet, First European Conference, ServiceWave 2008},
   editor = {M{\"a}h{\"o}nen Petri and Pohl Klaus and Priol Thierry},
   publisher = {Springer Berlin Heidelberg},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science},
   pages = {196--207},
   type = {Conference Paper},
   month = {December},
   year = {2008},
   isbn = {10.1007/978-3-540-89897-9_17},
   keywords = {Service Value Network, Key Performance Indicator, Business Process Management, Business Activity Monitoring},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://www.servicewave.eu/},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Networks of interdependent organizations cooperate to produce goods or, nowadays, services that are of value to their markets as well as to the participating organizations. Such co-operations can be supported by corresponding business processes which are based on SOA technology. Developing and managing SOA-based business processes in such service networks necessitates a comprehensive architecture which is on the one hand grounded on solid design principles, and on the other hand capturing best-practices and experiences. Such an architecture is currently lacking. This paper outlines a first attempt to develop and validate an architecture for developing, monitoring, measuring and optimizing SOA-enabled business processes in service networks. A case study from the telecommunications industry is analyzed, and different aspects of service networks are addressed.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-120&engl=1}
}
@inproceedings {INPROC-2008-12,
   author = {Gero Decker and Oliver Kopp and Frank Leymann and Kerstin Pfitzner and Mathias Weske},
   title = {{Modeling Service Choreographies using BPMN and BPEL4Chor}},
   booktitle = {Proceedings of the 20th International Conference on Advanced Information Systems Engineering (CAiSE '08)},
   publisher = {Springer-Verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science},
   volume = {5074},
   pages = {79--93},
   type = {Conference Paper},
   month = {June},
   year = {2008},
   doi = {10.1007/978-3-540-69534-9_6},
   keywords = {BPEL4Chor; BPMN; Choreography},
   language = {English},
   cr-category = {H.4.1 Office Automation,     K.1 The Computer Industry},
   ee = {http://www.lirmm.fr/caise08/},
   contact = {kopp@iaas.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Interconnecting information systems of independent business partners requires careful specification of the interaction behavior the different partners have to adhere to. Choreographies define such interaction constraints and obligations and can be used as starting point for process implementation at the partners' sites. This paper presents how the Business Process Modeling Notation (BPMN) and the Business Process Execution Language (BPEL) can be used during choreography design. Step-wise refinement of choreographies to the level of system configuration is supported through different language extensions as well as a mapping from BPMN to BPEL4Chor. A corresponding modeling environment incorporating the language mapping is presented.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-12&engl=1}
}
@inproceedings {INPROC-2008-116,
   author = {J{\"o}rg Nitzsche and Barry Norton},
   title = {{Ontology Based Data Mediation in BPEL (for Semantic Web Services)}},
   booktitle = {Proceedings of Business Process Management Workshops},
   publisher = {Springer Verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Workshop Paper},
   month = {September},
   year = {2008},
   keywords = {BPEL; Mediation},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {The Business Process Execution Language (BPEL) uses XML to specify the data used within a process and realizes data flow via (globally) shared variables. Additionally, assign activities can be used to copy (parts of) variables to other variables using techniques like XPath or XSLT. BPEL for Semantic Web Services (BPEL4SWS) employs SAWSDL to give meaning to data by referring to ontological concepts and to enable a seamless mapping of XML data and its ontological representation. In this paper we show how this ontological knowledge can be used to ease the definition of data flow in BPEL.We therefore extend BPEL and introduce the concept of mediaton as a first class citizen. We give an example of data mediation in BPEL processes and show how process modellers can benefit from the ontological knowledge when specifying data manipulation declaratively instead of having to implement data manipulation each time a process is modelled.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-116&engl=1}
}
@inproceedings {INPROC-2008-115,
   author = {J{\"o}rg Nitzsche and Benjamin H{\"o}hersteiger and Frank Leymann and Mirko Sonntag and Markus Tost},
   title = {{Defining the Behaviour of BPELlight Interaction Activities Using Message Exchange Patterns}},
   booktitle = {Proceedings of the Service Wave 2008},
   publisher = {Springer Verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {275--286},
   type = {Conference Paper},
   month = {December},
   year = {2008},
   doi = {10.1007/978-3-540-89897-9_24},
   keywords = {BPEL},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://www.servicewave.eu},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {BPEL light is an extension of BPEL that allows defining executable business processes independant of WSDL port types and operations. However, it adopts BPELs principle of having either non-blocking activities that only send or receive a single message or blocking activities, that are restricted to at most two messages, i.e. they implement a send-receive or receive-send behaviour. In recent work BPEL light has been used to define arbitrary complex message exchange patterns. In this paper we use message exchange patterns defined in BPEL light to describe the behaviour of interaction activities in a generic manner. This is beneficial as complex behaviour like a ``request-for-bid'' only have to be modelled once on an abstract level and can then be reused by simply referencing the corresponding message exchange pattern and filling in parameters whenever needed. This makes process modelling more convenient as the modelling primitives are not restricted to a request-response behaviour but are lifted to a business oriented level.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-115&engl=1}
}
@inproceedings {INPROC-2008-112,
   author = {Steffen Volz and Daniela Nicklas and Matthias Grossmann and Matthias Wieland},
   title = {{On creating a spatial integration schema for global, context-aware applications}},
   booktitle = {Proceedings of the X Brazilian Symposium on GeoInformatics (GeoInfo2008)},
   publisher = {INPE},
   institution = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   type = {Conference Paper},
   month = {December},
   year = {2008},
   language = {English},
   cr-category = {H.2.4 Database Management Systems,     H.2.8 Database Applications},
   department = {University of Stuttgart, Institute of Architecture of Application Systems;     University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems},
   abstract = {The world of spatial data is split into individual data source islands that have different thematic or spatial focuses. When attempting to integrate those data sources, severe challenges arise, since for most GIS application domains a spatial integration schema does not exist. This is also true for the newly emerging domain of mobile, context-aware applications. Since the users of these systems are mobile, transborder access to spatial data or context models is crucial for global deployment. The basis for this work is the Nexus Augmented World Schema, a conceptual schema that serves as an integration standard for autonomous spatial context servers. This paper analyzes some major spatial data standards, especially with respect to the requirements of a spatial integration schema for context-aware applications and illustrates the Nexus approach.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-112&engl=1}
}
@inproceedings {INPROC-2008-111,
   author = {Matthias Wieland and Daniela Nicklas and Frank Leymann},
   title = {{Managing Technical Processes Using Smart Workflows}},
   booktitle = {Towards a Service-Based Internet, First European Conference, ServiceWave 2008, Madrid, Spain, December 10-13, 2008. Proceedings},
   editor = {Petri Maehoenen and Klaus Pohl and Thierry Priol},
   publisher = {Springer Verlag},
   institution = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   series = {Lecture Notes in Computer Science},
   volume = {5377},
   pages = {287--298},
   type = {Conference Paper},
   month = {December},
   year = {2008},
   isbn = {978-3-540-89896-2},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   department = {University of Stuttgart, Institute of Architecture of Application Systems},
   abstract = {Technical processes that are crossing the boundary to the physical world can be found in many application domains, like logistics or in Smart Factory environments. We show how these processes can be realized by so-called Smart Workflows. To integrate external information sources like context provisioning services, we introduce the Integration Process architecture pattern. This pattern generally solves the problem of integrating different complex systems that provide functional similar services with non-fitting interfaces into workflows. The pattern allows that workflows use simple domain specific interfaces that are the same for any of these systems and by that allow the exchange of underlying systems without changing the workflows. This is accomplished by reducing the interface complexity of the systems via a hierarchical Web Service stack that reaches from the lowest technical granularity needed by IT experts to the domain specific granularity needed by the domain experts. Furthermore the paper presents a concrete realization of the pattern for integrating different context provisioning systems into workflows.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-111&engl=1}
}
@inproceedings {INPROC-2008-11,
   author = {Tobias Unger and Thomas Bauer},
   title = {{Towards a Standardized Task Management}},
   booktitle = {Multikonferenz Wirtschaftsinformatik 2008},
   editor = {Martin Bichler and Thomas Hess and Helmut Krcmar and Ulrike Lechner and Florian Matthes and Arnold Picot and Benjamin Speitkamp and Petra Wolf},
   publisher = {GITO-Verlag, Berlin},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {443--444},
   type = {Conference Paper},
   month = {February},
   year = {2008},
   isbn = {978-3-940019-34-9},
   keywords = {Task Management; BPEL4People; WS-HumanTask},
   language = {English},
   cr-category = {H.4.1 Office Automation},
   ee = {http://srvmatthes6.in.tum.de/tagungsbandArtikel.html,     http://ibis.in.tum.de/mkwi08/29_XML4BPM-XML_Integration_and_Transformation_for_Business_Process_Management/05_Unger-XML4BPM-long.pdf},
   department = {University of Stuttgart, Institute of Architecture of Application Systems}