Model-checking Web Services Orchestrations using BP-calculus

The Business Process Execution Language for Web Services (BPEL) is the standard for implementing orchestrated business processes designed but not limited to, as web services. BPEL is a powerful language but lacks a widely accepted formal semantics, and this makes it difficult to formally validate the correct execution of BPEL implementations. In the other hand, process algebras have proved their efficiency in the specification of web services orchestrations. In this paper we improve the BP-calculus, a π-calculus based formalism designed to ease the automatic generation of verified BPEL code, by defining specific equivalence and logic in order to verify BPEL implementations through their formal specification expressed in this calculus. The formal specification of service-oriented applications allows the checking of functional properties described by means of the new logic, that is shown to be well suited to capture peculiar aspects of services formalized in π-like languages. As an illustrative example, we present the BP-calculus specification and the verification results of a trade market service scenario.