Modeling, verifying and reasoning about web services

This paper describes the research activities carried out in the context of the Italian MIUR Project PRIN 2005 “Specification and verification of agent interaction protocols”, concerning the area of modeling, verification and reasoning about web services. Web services are an emergent paradigm for implementing business collaborations over the web. Each service has an interface that is accessible through standard protocols and that describes the interaction capabilities of the service. It is possible to develop new applications by combining and integrating existing web services. In this scenario, various languages have been developed for modeling processes and their interaction protocols. In particular, the language WS-BPEL has emerged as the standard for specifying the business processes of single services, while the global view of the interaction is captured by the concept of choreography, expressed by using specific languages like WS-CDL. Nowadays, in many application domains it is getting more and more common describing and realizing the offered services by means of a set of communicating agents. Techniques for the specification and verification of the interactive behavior of open agent systems find an immediate application in web services. The goal of our project is to prove the usefulness and the applicability of techniques based on declarative approaches for tackling issues typical of the web service application area. Our claim is that web service interactions should be represented according to some formalism which relies on well-founded models with a clear semantics. Furthermore, automated tools for reasoning about such a description and performing tasks of interest must be developed. The goal of the project is pursued through three main steps: