A QoS-Aware Service Composition Optimization Based on Logical Structure

Web service composition integrating several single services by logical structure can fulfill users´ complex requests while a single one cannot do this. As one of service´s nonfunctional components, quality of service (QoS) can be used as the criteria for service selection process and evaluation of composition results. However, so far there is no suitable method to estimate composition result and existing approaches on QoS-aware service composition don´t concern the effect of composition logic on composition consequences. This paper presents an approach to optimize a QoS-aware service composition based on the logical structure. With our approach, a global optimization consequence can be attained by displacing the single service component in a composition process, which is according to the flexibility of service execution duration under parallel logic. Moreover some experimental results illustrate that the proposed approach works effectively.