ATL Based Refinement of WS-CDL Choreography into BPEL Processes

Web services are often combined together to provide richer features for designing safer and more reliable systems. The composition of services is intended to inter-operate, interact and coordinate multiple services for the achievement of a global goal, or provide new service functions in general. The process for creating such composite services from existing ones is called Web services composition whose description may be achieved through a choreography which globally specifies the interactions between participating services. However, a composition is actually achieved using processes called orchestrators whose actions implement the needed calls to combined services. In this paper, we choose CDL and BPEL as specification languages for choreography and orchestration, respectively. The paper proposes a refinement of CDL choreographies into executable BPEL orchestrations using metamodel-driven translation technique that consists of a set of ATL rules. We propose a solution to transform a given choreography into a set of orchestrations, which exploits CDL and BPEL meta-models. We then propose and implement a set of translation rules using the language ATL, which refines a given CDL specification into a BPEL orchestration processes.