Automata for analysing service contracts

A novel approach to the formal description of service contracts is presented in terms of automata.We focus on the basic property of guaranteeing that in the multi-party composition of principals each individual gets his requests satisfied, so that the overall composition reaches its goal. Depending on whether requests are satisfied synchronously or asynchronously, we construct an orchestrator that at static time either yields composed services enjoying the required properties or detects the individuals responsible for possible violations. To do that in the asynchronous case we resort to techniques from Operational Research.