An Approach for Composing Web Services on Demand

The Web services composition plays a more and more important role in SOA environment nowadays. Composing Web services on user´s demand proves to be essential for both B2B and B2C applications. However, existing composition approaches and services composition description languages, such as BPEL4WS, are insufficient for satisfying user requirements. In this paper, we present an approach for Web services composition on demand. Our approach defines a description language for describing user´s demand and supporting dynamic services binding for flexible service composition, and applies SLA to service discovery that can automatically adapt the change of QoS constraints. The description language can be applied to any process-oriented composition language that supports executable business processes. Finally, our approach is applied to a service grid system where it provides a fully automatic, stable service composition on user´s demand