Representing service-relationships as first class entities in service orchestrations

Service orchestration approaches are widely used to composing multiple business services (partner services) into a business process to achieve a particular business objective. The business relationships captured in such a service orchestration are primarily those between the partner services and the business process itself. This however results in tight-coupling between processes and partner services and inadequate capturing of relationships between partner services that participate in an orchestration. These limitations create problems concerning the stability and runtime adaptability of a service orchestration. To address these limitations, we propose in this paper an approach that represents the service-relationships as first-class entities in service orchestrations during design-time and runtime. It provides the required stability and improves the runtime adaptability for service orchestrations amidst changing business requirements. A novel process enactment platform supporting the approach has been implemented by further extending the Apache Axis2 Web service engine.