A Coloured Petri Net Approach to Model and Analyse Stateful Workflows Based on WS-BPEL and WSRF

摘要

Composite Web services technologies are widely used due to their ability to provide interoperability among services from different companies. Web services are usually stateless, which means that no state is stored from the clients viewpoint. However, some new applications and services require to capture the state of some resources after each computation. Thus, new standards to model Web services states have emerged e.g. Web Services Resource Framework (WSRF). In this paper, we present a formal model based on WS-BPEL and WSRF, and we provide a prioritised-timed coloured Petri net semantics for it. This semantics captures the main activities of WS-BPEL, but we also consider other important aspects, both from WS-BPEL and WSRF, such as fault handling, resource management, time-outs and a publish-subscribe system.