Using assumptions in service composition context

Service composition aims to provide an efficient and accurate model of a service, based on which the global service oriented architecture (SOA) can be realized, allowing value added services to be generated on the fly. Unlike a traditional software module, which runs within a predictable domain, Web Services are autonomous software agents running in a heterogeneous execution environment. Because of distributed responsibilities, ownership and control, it is often not feasible to acquire all information needed for the service composition. These characteristics of autonomy and heterogeneity are fundamental to service oriented computing but make it inherently difficult to avoid service conflicts. To reason about and adapt to a changing environment, in this work, we will extend current OWL-S by introducing the concept of service assumptions which allow reasoning with incomplete information. Furthermore, together with the proposed service assumptions, a sequence of rule conditions are proposed to describe all permitted behaviors in service composition context.