Goal-driven context-aware service composition

Two important aspects are associated with service composition. One is to understand the needs and constraints for a new added-value composite service, and otherwise it would lead to an ad-hoc effort for service composition. The second is to reflect the changes of computing environment to the service composition to catch up the on-demand of users. This paper introduces a goal-driven approach to specify the user requirements and demands that guides the service composition, and proposes context awareness to adapt to a dynamically changing environment. Computing contexts, including physical context, user profile and computed results, are gathered by various services, and imported into an ontology based a context repository. A Goal Description Language, Context Condition/Effect are designed to describe the dynamic semantics of goal requirements and service capability. A planner is designed and implemented to dynamically compose services based on the current contexts, and a service runner is designed and implemented to invoke proper services based on the contexts and interactions with users.