A Model-based Approach for Diagnosing Faults in Web Service Processes

Web services based on a service-oriented architecture framework provide a suitable technical foundation for business process management and integration. A business process can be composed of a set of Web services that belong to different companies and interact with each other by sending messages. Web service orchestration languages are defined by standard organizations to describe business processes composed of Web services. A business process can fail for many reasons, such as faulty Web services or mismatching messages. It is important to find out which Web services are responsible for a failed business process because we could penalize these Web services and exclude them from the business process in the future. In this paper, we propose a model-based approach to diagnose the faults in a Web service-composed business process. We convert a Web service orchestration language, more specifically BPEL4WS, into synchronized automata, so that we have a formal description of the topology and variable dependency of the business process. After an exception is thrown, the diagnoser can calculate the business process execution trajectory based on the formal model and the observed evolution of the business process. The faulty Web services are deduced from the variable dependency on the execution trajectory. We demonstrate our diagnosis technique with an example. •t