Transforming Web Services Choreographies with priorities and time constraints into prioritized-time colored Petri nets

A Web Service is a self-describing, self-contained modular application that can be published, located, and invoked over a network, such as the Internet. Web Service composition provides a way to obtain value-added services by combining different existing facilities, which are then able to support the integration of commercial applications. WS-CDL (Web Services Choreography Description Language) is a W3C candidate recommendation for the description of peer-to-peer collaborations by participants in a Web Services composition. This paper focuses on several important aspects of WS-CDL, namely, data variables, timed restrictions, as well as the priorization of collaborations. In WS-CDL there are no priorities, thus, one of our first goals is to provide a WS-CDL definition of prioritized collaborations. We also define a semantics of WS-CDL (with priorities) by means of prioritized-timed colored Petri nets.