A Petri Net Approach to Analysis and Composition of Web Services

Abstract

Business Process Execution Language for Web Services (BPEL) is becoming the industrial standard for modeling web service-based business processes. Behavioral compatibility for web service composition is one of the most important topics. The commonly used reachability exploration method focuses on verifying deadlock-freeness. When this property is violated, the states and traces in the reachability graph only give clues to re-design the composition. The process must then repeat itself until no deadlock is found. In this paper, multiple web services interaction is modeled with a Petri net called Composition net (C-net for short). The problem of behavioral compatibility among web services is hence transformed into the deadlock structure problem of a C-net. If services are incompatible, a policy based on appending additional information channels is proposed. It is proved that it can offer a good solution that can be mapped back into the BPEL models automatically.