@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 = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {387--394},
type = {Konferenz-Beitrag},
month = {April},
year = {2012},
keywords = {patterns; confidentiality; database layer; migration; distributed application architecture; cloud data store},
language = {Englisch},
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 = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
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=0}
}
@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 = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {577--584},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {2011},
doi = {10.1109/DASC.2011.106},
keywords = {cloud data hosting solution; taxonomy; distributed application architecture; database layer; cloud computing},
language = {Englisch},
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 = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
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=0}
}
@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 = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {73--80},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2011},
isbn = {978-0-7695-4463-2},
doi = {10.1109/ICWS.2011.70},
language = {Englisch},
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 = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
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=0}
}
@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 = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {CEUR Workshop Proceedings},
volume = {705},
pages = {58--64},
type = {Workshop-Beitrag},
month = {M{\"a}rz},
year = {2011},
language = {Englisch},
cr-category = {H.4.1 Office Automation},
ee = {http://zeus2011.aifb.kit.edu/},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
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=0}
}
@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 = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {CEUR Workshop Proceedings},
volume = {705},
pages = {26--33},
type = {Workshop-Beitrag},
month = {M{\"a}rz},
year = {2011},
language = {Englisch},
cr-category = {H.4.1 Office Automation},
ee = {http://zeus2011.aifb.kit.edu/},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
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=0}
}
@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 = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--7},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {2010},
language = {Englisch},
cr-category = {H.4.1 Office Automation},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
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=0}
}
@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 = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--6},
type = {Konferenz-Beitrag},
month = {November},
year = {2010},
language = {Englisch},
cr-category = {H.4.1 Office Automation},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
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=0}
}
@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 = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Lecture Notes in Informatics},
volume = {P-177},
pages = {267--279},
type = {Konferenz-Beitrag},
month = {September},
year = {2010},
language = {Englisch},
cr-category = {H.4.1 Office Automation},
ee = {http://www.bpsc-conf.org/},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
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=0}
}
@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 = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Konferenz-Beitrag},
month = {Oktober},
year = {2010},
language = {Englisch},
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 = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
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=0}
}
@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 = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {CEUR Workshop Proceedings},
volume = {563},
pages = {25--31},
type = {Workshop-Beitrag},
month = {M{\"a}rz},
year = {2010},
language = {Deutsch},
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 = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
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=0}
}
@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 = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {CEUR Workshop Proceedings},
volume = {563},
pages = {97--104},
type = {Workshop-Beitrag},
month = {M{\"a}rz},
year = {2010},
language = {Deutsch},
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 = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
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=0}
}
@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 = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
type = {Workshop-Beitrag},
month = {September},
year = {2010},
language = {Englisch},
cr-category = {H.4.1 Office Automation},
contact = {unger@iaas.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
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=0}
}
@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 = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {927--932},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {2010},
isbn = {978-1-4244-6788-4},
doi = {10.1109/PIC.2010.5687886},
language = {Englisch},
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 = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
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=0}
}
@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 = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {1--8},
type = {Konferenz-Beitrag},
month = {Dezember},
year = {2010},
language = {Englisch},
cr-category = {H.4.1 Office Automation},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
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=0}
}
@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 = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Lecture Notes in Computer Science},
volume = {6275},
pages = {358--369},
type = {Workshop-Beitrag},
month = {November},
year = {2009},
language = {Englisch},
cr-category = {H.4.1 Office Automation},
ee = {http://www.s-cube-network.eu/MONA2/},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
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=0}
}
@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 = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Lecture Notes in Computer Science},
volume = {5870},
pages = {357--364},
type = {Konferenz-Beitrag},
month = {November},
year = {2009},
language = {Englisch},
cr-category = {K.4.4 Electronic Commerce,
H.4.1 Office Automation},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
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=0}
}
@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 = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Lecture Notes in Computer Science},
volume = {5900},
pages = {445--454},
type = {Konferenz-Beitrag},
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 = {Englisch},
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 = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
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=0}
}
@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 = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {Lecture Notes in Computer Science},
volume = {5870},
pages = {398--405},
type = {Konferenz-Beitrag},
month = {November},
year = {2009},
doi = {10.1007/978-3-642-05148-7_29},
keywords = {Process Managment; Process Adaption; Process Flexibility},
language = {Englisch},
cr-category = {D.2.2 Software Engineering Design Tools and Techniques,
F.4.1 Mathematical Logic},
contact = {hanna.eberle@iaas.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
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=0}
}
@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},
publisher = {IEEE},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {131--140},
type = {Konferenz-Beitrag},
month = {September},
year = {2009},
keywords = {multi-tenancy; SaaS; services; SOA; composite applications},
language = {Englisch},
cr-category = {D.2.11 Software Engineering Software Architectures,
H.4.1 Office Automation},
contact = {ralph.mietzner@iaas.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
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=0}
}
@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 = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {405--412},
type = {Konferenz-Beitrag},
month = {Juli},
year = {2009},
doi = {10.1109/ICWS.2009.82},
isbn = {978-0-7695-3709-2},
keywords = {Business Process Management; BPM; BPEL; Enforcement},
language = {Englisch},
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 = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen;
Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Verteilte Systeme},
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=0}
}
@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 = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {43--52},
type = {Konferenz-Beitrag},
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 = {Englisch},
cr-category = {H.4.1 Office Automation},
ee = {http://ieeexplore.ieee.org/search/wrapper.jsp?arnumber=4634756},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
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=0}
}
@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 = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {443--444},
type = {Konferenz-Beitrag},
month = {Februar},
year = {2008},
isbn = {978-3-940019-34-9},
keywords = {Task Management; BPEL4People; WS-HumanTask},
language = {Englisch},
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 = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {Business processes are increasingly controlled by IT-systems automatically, but
they still consist of many tasks that have to be performed by people. Despite
an appropriate IT-infrastructure is required for Task Management, until now
this is a neglected topic in the research domain. In general, existing concepts
and products for Task Management are not sufficient and, even worse,
inter-partner aspects are not supported at all. For the first time, this paper
analyzes the requirements for Task Management in a comprehensive way.
Furthermore, we present an architecture for a Task Management Infrastructure
that allows to fulfill these requirements even in inter-partner scenarios. This
architecture was developed in the TAMPRO project and is based on emerging
standards as WS-HumanTask and BPEL4People, which are discussed as well.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2008-11&engl=0}
}
@inproceedings {INPROC-2007-69,
author = {Oliver Kopp and Hanna Eberle and Frank Leymann and Tobias Unger},
title = {{From Process Models to Business Landscapes}},
booktitle = {EPK 2007: Gesch{\"a}ftsprozessmanagement mit Ereignisgesteuerten Prozessketten},
editor = {Markus N{\"u}ttgens and Frank J. Rump Rump and Andreas Gadatsch},
publisher = {Online},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
series = {CEUR Workshop Proceedings},
volume = {303},
pages = {7--22},
type = {Workshop-Beitrag},
month = {Dezember},
year = {2007},
keywords = {FMC, EPK, EPC, architecture},
language = {Englisch},
cr-category = {H.4.1 Office Automation},
ee = {http://sunsite.informatik.rwth-aachen.de/Publications/CEUR-WS/Vol-303/},
contact = {kopp@iaas.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {Today, architecture and business processes are modeled separately. The only
integration in architectural diagrams is done with Petri nets in the
Fundamental Modeling Concept. Since business users prefer EPCs over Petri nets,
we show how information of extended EPCs can be transformed into business
landscapes. This facilitates development of IT landscapes satisfying the
requirements of the business process and adoption of existing IT
infrastructures to new requirements.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2007-69&engl=0}
}
@inproceedings {INPROC-2006-66,
author = {Oliver Kopp and Tobias Unger and Frank Leymann},
title = {{Nautilus Event-driven Process Chains: Syntax, Semantics, and their mapping to BPEL}},
booktitle = {Proceedings of the 5th GI Workshop on Event-Driven Process Chains (EPK 2006)},
editor = {M. N{\"u}ttgens and F.J. Rump and J. Mendling},
address = {Vienna, Austria},
publisher = {CEUR-WS.org},
institution = {Universit{\"a}t Stuttgart, Fakult{\"a}t Informatik, Elektrotechnik und Informationstechnik, Germany},
pages = {85--104},
type = {Workshop-Beitrag},
month = {Dezember},
year = {2006},
keywords = {Nautilus; EPC; BPEL; mapping},
language = {Englisch},
cr-category = {H.4.1 Office Automation,
K.1 The Computer Industry},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2006-66/INPROC-2006-66.pdf,
http://www.epk-community.de/},
contact = {Oliver.Kopp@iaas.uni-stuttgart.de},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {Nautilus Event-driven Process Chains (N-EPCs) are a variant of Eventdriven
process chains allowing multiple events between functions. This allows events
to be used as transition conditions in a mapping to the Business Process
Execution Language for Web Services (BPEL). We will give a formal definition of
N-EPCs and show how they can be mapped to BPEL. A close look will be taken how
connectors can be eliminated while preserving their semantics.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2006-66&engl=0}
}
@article {ART-2011-18,
author = {Oliver Kopp and Katharina G{\"o}rlach and Dimka Karastoyanova and Frank Leymann and Michael Reiter and David Schumm and Mirko Sonntag and Steve Strauch and Tobias Unger and Matthias Wieland and Rania Khalaf},
title = {{A Classification of BPEL Extensions}},
journal = {Journal of Systems Integration},
publisher = {Online},
volume = {2},
number = {4},
pages = {2--28},
type = {Artikel in Zeitschrift},
month = {November},
year = {2011},
issn = {1804-2724},
keywords = {BPEL Extension; Classification of Extensions; Extension Guidelines},
language = {Englisch},
cr-category = {H.4.1 Office Automation},
ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2011-18/ART-2011-18.pdf,
http://www.si-journal.org/index.php/JSI/article/view/103},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {The Business Process Execution Language (BPEL) has emerged as de-facto standard
for business processes implementation. This language is designed to be
extensible for including additional valuable features in a standardized manner.
There are a number of BPEL extensions available. They are, however, neither
classified nor evaluated with respect to their compliance to the BPEL standard.
This article fills this gap by providing a framework for classifying BPEL
extensions, a classification of existing extensions, and a guideline for
designing BPEL extensions.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2011-18&engl=0}
}
@article {ART-2010-06,
author = {Ralph Mietzner and Frank Leymann and Tobias Unger},
title = {{Horizontal and Vertical Combination of Multi-Tenancy Patterns in Service-Oriented Applications}},
journal = {Enterprise Information Systems - 13th International IEEE EDOC Enterprise Computing Conference (EDOC 2009)},
publisher = {Taylor \& Francis},
volume = {4},
number = {3},
pages = {1--18},
type = {Artikel in Zeitschrift},
month = {Juli},
year = {2010},
doi = {10.1080/17517570903033431},
isbn = {ISSN 1751-7583},
language = {Englisch},
cr-category = {H.4.1 Office Automation},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {Software as a service (SaaS) providers exploit economies of scale by o ering
the same instance of an application to multiple customers typically in a
single- instance multi-tenant architecture model. Therefore the applications
must be scalable, multi-tenant aware and con gurable. In this paper we show how
the services in a service-oriented SaaS application can be deployed using
di erent multi-tenancy patterns. We describe how services in di erent
multi-tenancy patterns can be composed on the application level. In addition to
that, we also describe how these multi-tenancy patterns can be applied to
middleware and hardware components. We then show with some real world examples
how the di erent multi-tenancy patterns can be combined.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2010-06&engl=0}
}
@article {ART-2009-12,
author = {Tobias Unger and Ralph Mietzner and Frank Leymann},
title = {{Customer-defined Service Level Agreements for Composite Applications}},
journal = {Enterprise Information Systems - Towards Model-driven Service-oriented Enterprise Computing – 12th International IEEE EDOC Enterprise Computing Conference (EDOC 2008)},
publisher = {Taylor \& Francis},
volume = {3},
number = {3},
pages = {369--391},
type = {Artikel in Zeitschrift},
month = {August},
year = {2009},
doi = {10.1080/17517570903033431},
isbn = {ISSN 1751-7583},
language = {Englisch},
cr-category = {H.4.1 Office Automation},
ee = {http://www.informaworld.com/smpp/content~db=all?content=10.1080/17517570903033431},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Architektur von Anwendungssystemen},
abstract = {One key factor for successfully outsourcing of applications to a provider is to
guarantee a certain level of service. Hence, service provider and service
consumer agree on Service Level Agreements (SLA) that definne the behavior and
quality of the non-functional properties. Unlike many existing approaches,
which only allow the customer to choose between a small set of predefined
service levels, our approach helps to cope with the situation that customers
want to model their own service level according to their individual business
needs. As a first step, we introduce an application model which enables the
outsourcing of applications. In addition, we present corresponding models for
describing QoS requirements and SLAs. To assure the requested QoS, the provider
has to determine the QoS requirements of each application component. In this
work, we determine the QoS requirement of a component by disaggregating the QoS
requirements stated in the SLA. After the disaggregation the provider deploys
each component of the application in an optimal way based on its QoS
requirements, determined during the disaggregation.},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2009-12&engl=0}
}