Making BPEL Flexible – Adapting in the Context of Coordination Constraints Using WS-BPEL

While WS-BPEL is emerging as the prominent language for modeling executable business processes, it provides limited support for designing flexible processes. An important need of adaptive processes is for concurrent activities in the process to respect coordination constraints. These require that concurrent activities coordinate their behaviors in response to events otherwise the process may become inconsistent. We show how the constraints that necessitate coordination may be represented in WS-BPEL, and use generalized adaptation and constraint enforcement models to provide a way to transform the traditional BPEL process to an adaptive one. The final outcome is an executable WSBPEL process without extensions capable of executing on standard BPEL implementations and able to adapt to events while respecting coordination constraints.