One of the main tasks of workflow management systems is the coordination of activities in business processes. In this paper, a solution framework is introduced to support adaptive workflows with complex and unstructured task dependencies. In chapter one the research direction is motivated and a short overview of the PoliFlow project is given. Then, requirements for enterprise process management systems are identified with a special focus on coordination and control of unstructured processes. Taking these requirements as a basis, an integrated approach for adaptive workflow support is presented. A flexible workflow model including advanced control structures allows actors to modify workflow instances during runtime. Finally, a reference architecture is proposed. By example of the SWATS system, it is illustrated how an adaptive support layer can be integrated to extend existing workflow management systems. The paper concludes with an overview over the current state of the work and future issues.