Towards Automated Conformance Checking of ebBP-ST Choreographies and Corresponding WS-BPEL Based Orchestrations

Web Services technologies are a natural candidate for Business-to-Business integration (B2Bi). For crossorganizational processes, the concepts of “choreography” and “orchestration” are important. The term choreography denotes a model of a global view over message exchange scenarios, whereas the term orchestration focuses on models of the local implementation. While WS-BPEL is already kind of a de-facto standard in the field of orchestration languages, there does not exist a standard choreography language. We propose the usage of ebXML BPSS (ebBP) in order to provide choreography modeling at the business level. A frequent problem is to ensure and enforce the consistency and conformance of choreography and orchestration models which is often referred to as “conformance checking”. In this paper we examine a way to check the conformance between ebBP-ST (a subset of ebBP) choreographies and corresponding WS-BPEL based implementations. To achieve this check well-known and approved model checking methods and tools are used: First ebBP-ST choreographies are directly transformed into the process algebra CCS. Second, the low level WS-BPEL processes are analyzed for code blocks that implement choreography elements and the sequence of these code blocks is then mapped to CCS, too. Afterwards these formalized representations will be checked for bisimulation equivalence in order to reveal inconsistencies between the choreography and their implementations.