An UML _AD-to-event_B refinement based approach for specifying and verifying workflow applications

In this paper, we propose an approach for the specification and the verification of workflow applications using UML AD and Event B. Workflow carries applications where many actors take part and cooperate in order to execute operations. Upon composing those operations, many problems such as deadlock, freeness and livelock might appear. In this context, we are going to show how to express an UML Activity Diagram model in Event B. In our approach, the workflow is initially expressed incrementally graphically with UML AD, then translated into Event B and verified using the B powerful support tools. The Event-B expression of the UML AD model allows us to give it a precise semantics. We propose a workflow applications constructive approach in witch Event B models are built incrementally from UML AD models, driven by UML refinement patterns. The use of the B formal method and its refinement mechanism allows the verification of the correction of the UML AD refinement patterns.