Conceptual Modeling of Web Service Conversations

Web services are emerging as a promising technology for the effective automation of inter-organizational interactions. Several standards that aim at providing infrastructure to support Web services description, discovery, and composition have recently emerged including WSDL, UDDI, and BPEL4WS. Indeed, advances in this area promise to take cross-organizational application integration a step further by facilitating the automatic discovery and invocation of relevant services. However, despite the growing interest in Web services, several issues still need to be addressed to provide similar benefits to what traditional middleware brings to intra-organizational application integration (e.g., transaction support). In this paper, we identify a framework for defining extended service models to enable the definition of richer Web service abstractions. We also identify and define specific abstractions based on an analysis of existing e-commerce Web portals. Finally, we show how the model and the abstractions are supported by a conversation manager implemented on top of the SELF-SERV platform.