Message Correlation in Web Services Choreographies: A 4-phase Validation Method

The majority of large companies are adopting Service Oriented Architectures, mainly to automate their business processes, both centralized and distributed. This paper will focus on distributed business processes. At the moment there are two interesting ways to implement a distributed business process, via orchestration or choreography. Whereas an orchestration can be thought of as a service composition with a single participant taking the lead, a choreography is a decentralized collaboration between different autonomous participants. One of the most prominent remaining issues, associated with both approaches, is the correlation problem, which is addressed in this paper. We will show that the abstract overall view, provided by a choreography description, makes it possible to determine (even at design time) whether its interactions can be unambiguously correlated. It is shown that this correlation validation is more feasible to realize in case of choreographies than with orchestrations, due to the orchestration's limited view on the overall business process.