Verification and validation of web service composition using event B method

Abstract

The Service-Oriented Architecture based on the Web service technology emerged as a consequence of the evolution of distributed computing. One of the key ideas of this technology is the ability to create service compositions by combining and interacting with pre-exisiting services. A service is implemented, described[1], and published by a service provider in a UDDI[2] registry. The service composition is referred to an executable process that interacts with other services accomplishing its functional goal. Orchestration and Choreography[3] are the processes that allow to schedule the defined services compositions and messages exchanges. There is a wide range of industrial standardization efforts towards providing specification languages for the Web service composition. Among them BPEL (Business Process Execution Language[4]) is the most known and used orchestration language. Our work addresses the composition expressed by the orchestration and its support language BPEL. BPEL allows the designer to represent service compositions by various behavioral properties like services interactions (message exchanges), control flow constraints (sequence, iteration, conditional) or data flow constraints (exchange, modification, evaluation of data expressions). © 2008 Springer-Verlag Berlin Heidelberg.