A Colored Petri Nets Model for Diagnosing Semantic Faults of BPEL Services ?

The paper contributes to modeling an orchestrated complex Web Service (BPEL) with Colored Petri Nets (CPNs) for diagnosis. In the CPNs model, colored tokens are used to represent the faults in a BPEL process. A uniform fault model is introduced to represent both the faulty input data and external faulty Web services called by the BPEL activities. We use three I/O data dependency relations for each BPEL activity. To represent the fault propagation in colored Petri nets, we define the color propagation functions for each data dependency relation. We give a concrete translation from a BPEL service to a CPNs model. Model-based diagnosis framework is then used. Based on the evolution equation in Petri nets theory, we construct an inequations system as a diagnosis problem and solve it with an algebra algorithm.