business process execution language (BPEL)

The Business Process Execution Language (BPEL or WS-BPEL), formerly BPEL4WS, is a joint proposal by IBM and Microsoft to drive standardization for the control and coordination of business-based Web services. BPEL for Web services competes with the Business Process Management Initiative( BPMI) with its Business Process Modeling Language (BPML), but appears to be gaining acceptance as a standard.

BPEL, which is based on the Extensible MarkupLanguage(XML), can be used to modulate business processes in the form of Web service chains and to prepare them for coordination with business partners. In doing so, BPEL defines the interface protocol, which specifies the sequence of dialog steps, and describes the communication with business partners.

BPEL was designed by OASIS in version 1.1 and, like the Web Service Choreography Interface(WSCI) from the World Wide Web Consortium(W3C), supports various functions for the coordination and orchestration of Web services. These include defining message exchange models to invoke Web services, describing the logic and state required for orchestration, correlatingmessages and orchestration steps, discovering faulty or incomplete orchestration instances, initiating, performing, controlling, suspending, terminating, and canceling orchestrated Web services, and defining orchestrations as reusable Web services.