Formal Modeling and Conformance Validation for WS-CDL using Reo and CASM

WS-CDL is a choreography language that describes peer-to-peer collaborations of participants by defining their common and complementary observable behaviors from a global viewpoint. The main use of a choreography description is to precisely define the sequence of interactions between a set of cooperating web services in order to promote a common understanding between participants and to make it easy to automatically validate conformance and ensure interoperability. To this purpose, WS-CDL must be based on or related to a formal language that provides these validation capabilities. In this paper, we benefit from Reo and Constraint Automata with State Memory (CASM) to address this problem by providing a unified formalism for choreography and orchestration. Furthermore, we show how to exploit this formalism for conformance validation by giving proper definitions for end-point projection and conformance problem.