A Framework for Verifying SLA Compliance in Composed Services

Service level agreements (SLAs) impose many non-functional requirements on services. Business analysts specify and check these requirements in business process models using tools such as IBM WebSphere Business Modeler. System integrators on the other hand use service composition tools such as IBM WebSphere Integration Developer to create service composition models, which specify the integration of services. However, system integrators rarely verify SLA compliance in their proposed composition designs. Instead, SLA compliance is verified after the composed services are deployed in the field. To improve the quality of the composed services, we propose a framework to verify SLA compliance in composed services at design time. The framework re-uses information in business process models to simulate services and verify the non-functional requirements before the service deployment. To demonstrate our framework, we built a prototype using an industrial process simulation engine from IBM WebSphere Business Modeler and integrate it into an industrial service composition tool. Through a case study, we demonstrate that our framework and the prototype assist system integrators in composing services while considering the non-functional requirements.