An architecture for providing context in WS-BPEL processes

Abstract

Web Service Business Process Execution Language (WS-BPEL) business processes are increasingly used by organizations to automate their business activities. As the pace of change in an organization increases, these processes will be required to be more flexible; to do so they will have to account for an increasing amount of changing environment state, or context. This poses significant challenges for WS-BPEL programmers, who have to source, track, and update context from multiple entities in addition to implementing and maintaining core business logic. In this paper we present a solution to this problem based on the definition and use of context variables. We describe how context variables can be constructed using the WS-BPEL language extension mechanism, and then outline an architecture for representing, sourcing, and propagating context in a web-services environment using existing web-services standards and frameworks. We also propose additional WS-BPEL language enhancements that will increase the utility of context variables and offer WS-BPEL programmers new ways of interacting with environment state. We have implemented a prototype realizing our approach and present a purchase-and-shipping scenario as an example of its use.