A Survey of Formalization Approaches to Service Composition

Service-Oriented Computing (SOC) was introduced some years ago as a paradigm that allows companies to expose their core competencies as services. Yet, we can only benefit from the full potential of SOC if we explore the possibility of composing services. In practice, service composition enables the development of complex systems by combining existing services, which makes it possible to integrate business processes across different companies. Several languages have been defined to specify service compositions, such as WSBPEL and WS-CDL. However, these languages lack formal semantics, so that they do not allow the verification of the service composition behavior by means of properties such as the absence of deadlocks and livelocks. In this paper, we present a structured survey on initiatives in which formal description techniques were applied to specify and possibly verify service compositions. As a result of this study, we identified some open challenges and some topics for future work.