From WS-CDL choreography to BPEL process orchestration

The Web Service Choreography Description Language (WSCDL) is a specification for describing multi party collaboration based on Web Services from a global point of view. WS-CDL is designed to be used in conjunction with the Web Services Business Process Execution Language (WS-BPEL or BPEL). As WS-CDL is a new choreography language, there has been doubt on the feasibility of a transformation to BPEL. In this article, we show how BPEL process definitions of parties involved in a choreography can be derived from the global WS-CDL model and what the limitations of such a derivation are. We have implemented a prototype of the mappings as a proof of concept. The automatic transformation leverages the quality of software components interacting in the choreography as advocated in the Model Driven Architecture concept. The mapping reveals that some information has to be added manually to the generated BPEL, in particular, choice conditions and private activities. keywords: Choreography, Orchestration, Web Service, Business Process, Workflow, Inter-organizational Processes