Verifying BPEL-like Programs with Hoare Logic: Technical Report

The WS-BPEL language has recently become a de facto standard for modeling Web-based business processes. One of its essential features is the fully programmable compensation mechanism. To understand it better, many recent works have mainly focused on formal semantic models for WS-BPEL. In this paper, we make one step forward by investigating the verification problem for business processes written in BPEL-like languages. As a result of the exploration, we have proposed a set of Hoare-logic style inference rules which form as an axiomatic verification system for a core BPEL-like language containing key features such as data states, fault and compensation handling. We have also proposed a big-step operational semantics for such a core language where data states and fault/compensation handling features are all incorporated. Our verification rules are proven sound with respect to this underlying semantics. The application of the verification rules is illustrated via the proof search process for a nontrivial example.