Web service selection/composition based on PSOA: A review

There are lots of web services available to perform a particular task but they differ in their QoS values. Discovery mechanism selects the best web service according to their QoS values and functional attributes. A single web service may not satisfy a user´s complex query. In cases, where the discovery mechanism fails, web service composition is done to meet user´s complex query. In this paper, we have given a brief discussion on web services, discovery and composition also we have studied some evolutionary computing based discovery and composition focusing the Particle Swarm Optimization approach.