Web services are defined as the pieces of software components, which are distributed over the internet using some standard protocols. With more and more web services become available, QoS is a decisive factor for selecting the most suitable service from a set of candidate services with the identical functionality. Thus the approach about the computation of the QoS is also becoming more important in the service selection. In this paper, we use an algorithm called “Intelligent Water Drops” or IWD algorithm which is inspired from natural science. It is based on the processes that happen in the natural river system. The actions and reactions that take place between the water drops are also considered. The river often chooses an optimal path regarding the conditions of its surroundings to get its ultimate goal, which is often a sea. These ideas are embedded into the web service selection and composition for providing efficient QoS web services. This proposed algorithm provides better computing performance than Particle swarm optimization algorithm (PSO).
