Date Added: Jul 2012
The web services model has emerged as a standard for representation, discovery, and invocation of services in a distributed environment. During service composition, Selection of appropriate services for composition is the chief task. A series of tasks are tied together to form a composite web service. Such composition is a challenging task because a number of Web services with the same or similar functions are increasing rapidly. QoS plays a vital role in the problem of selecting the most appropriate web service for composition. It is a measure for how well the composite web service serves the requester. Particle Swarm Optimization (PSO) algorithm and Gravitational Search Algorithm can be used to resolve this problem of optimal service selection.