Choreography Conformance Checking: An Approach based on BPEL and Petri Nets

Recently, languages such as BPEL and CDL have been proposed to describe the way services can interact from a behavioral perspective. The emergence of these languages heralds an era where richer service descriptions, going beyond WSDL-like interfaces, will be available. However, what can these richer service descriptions serve for? This paper investigates a possible usage of behavioral service descriptions, namely as input for conformance checking. Conformance checking is the act of verifying whether one or more parties stick to the agreed-upon behavior by observing the actual behavior, e.g., the exchange of messages between all parties. This paper shows that it is possible to translate BPEL business protocols to Petri nets and to relate SOAP messages to transitions in the Petri net. As a result, Petri net-based conformance checking techniques can be used to quantify fitness (whether the observed behavior is possible in the business protocol) and appropriateness (whether the observed behavior “overfits” or “underfits” the business protocol). Moreover, non-conformance can be visualized to pinpoint deviations. The approach has been implemented in the context of the ProM framework.