A Quantitative and Qualitative Approach for NFP-Aware Web Service Composition

Web service composition is a standard approach to create value-added services from existing ones. As the Web services on the Internet grows, there are more and more services providing identical functionalities while differing in their non-functional properties (NFPs). However, most of the existing techniques for NFP-aware service composition consider either only quantitative NFPs or only qualitative NFPs. In this paper, we present a service composition model considering both quantitative and qualitative NFPs. We propose two algorithms for conducting service composition. One combines global optimization with local selection into one mechanism. The other is a genetic algorithm based solution. We have conducted extensive experiments to evaluate the effectiveness of our proposals.