Model-Based Analysis of Obligations in Web Service Choreography

In this paper we discuss a model-based approach to the analysis of service interactions for coordinated web service compositions using obligation policies specified in the form of Message Sequence Charts (MSCs) and implemented in the Web Service Choreography Description Language (WSCDL). The approach uses finite state machine representations of web service compositions (implemented in BPEL4WS) and service choreography rules, and assigns semantics to the distributed process interactions. The move towards implementing web service choreography requires design time verification of these service interactions to ensure that service implementations fulfill requirements for multiple interested partners before such compositions and choreographies are deployed. The described approach is supported by a suite of cooperating tools for specification, formal modeling, animation and providing verification results from choreographed web service interactions.