Selecting Web Services for Optimal Composition

Web services are modular applications that can be described, located and invoked on the Internet. A user request may not only correspond to one specific service, but also to a set of web services. Thus, it is necessary that a composition of services be done in order to obtain the expected result. Nonetheless, many services with the same goal but different characteristics can be discovered. Indeed, it is necessary to find non-functional criteria to distinguish them, in order for a user to be able to choose an optimal solution. In this paper, we propose service quality variables as non-functional criteria in order to make an optimal service composition for a goal. We propose then using multiobjective optimisation techniques to find a set of optimal Pareto solutions from which a user can choose the most interesting tradeoff. Finally, we introduce the environment which allows that this composition process be automatic.