Web services play a major role in electronic businesses and allow organizations to perform certain business activities in a distributed fashion. In some circumstances, a single service is not able to perform certain tasks and it becomes imperative to compose two or more services in order to complete a task. While approaches to tackle such a problem are known, the task of generating provably correct Web service compositions still remain challenging and complex. In this paper, we develop a supervisory control framework for automated composition of Web services. Labelled Transition Systems augmented with guards and data variables are used to represent a given set of Web service specifications. We model the interactions of services asynchronously and we use guards and data variables to allow us to express certain preconditions which are then propagated from the system requirements through the overall composite service. The objective of our framework is to synthesize a controller, which interacts with a given set of Web services through messages to guarantee that a given specification is satisfied. A key novelty of this work is the application of control theory to service-oriented computing and the incorporation of run-time input into the supervisor generation process.
['Francis Atampore', 'Juergen Dingel', 'Karen Rudie']
Automated service composition via supervisory control theory