Verification of Business Processes for Web Services

The Business Process Execution Language for Web Services (BPEL4WS or simply BPEL) is a recently developed language, which is used to specify interactions between web services. Among its features it allows specification of concurrent behavior. Erroneous specification can lead to such problems as deadlock. In our research we focus on the concurrency mechanism in BPEL. Our main goal is to analyze processes in order to detect possible deadlocks. To achieve this we introduce a process algebra called the BPE-calculus. It is a small language which captures all the BPEL features relevant to the analysis. This process algebra is modelled using a labeled transition system. An existing verification tool called the Concurrency Workbench is customized to use our BPE-calculus. This tool allows us to verify many properties of BPE-calculus processes specified in a logic called the μ-calculus, including deadlock freedom.