Conformance Validation between Choreography and Orchestration

Referring to the design and implementation of large service oriented systems, two different approaches, choreography and orchestration, need to be concerned and studied. Choreography is a specification protocol defining a global picture of the way services interact with each other. Whereas orchestration is a local view focusing on the behavior of a single service. A critical issue, the so called conformance problem, is to validate whether a specific orchestration can play as a participant whose observable behavior is required by a given choreography. In this paper, we introduce two languages for describing choreography and orchestration respectively. Based on the two languages, we give a definition of endpoint projection which is used for automatic generation of orchestrations. Therefore, conformance validation is reduced to verification of process refinement between two orchestrations. Further, we mention that not all choreography models can be locally implementable. In other words, some global models cannot be translated into sets of orchestrations satisfying the global behavioral rules. To ensure that a choreography model is locally implementable, some conditions are required to be satisfied. As a consequence of our work, the skeleton codes for service implementations can be automatically generated, on the other hand, the interoperability between collaborating services is guaranteed.