An approach for web services composition based on QoS and gravitational search algorithm

Web services composition based on QoS is the NP-hard problem, so the bionics optimization algorithms can solve it well. On the other hand, QoS of compound service is a key factor for satisfying the users. The users prefer different QoSs according to their desires. We have Proposed the services composition algorithm based on quality of services and gravitational search algorithm which is one of the recent optimization algorithms and it has many merits, for example rapid convergence speed, less memory use, considering a lot of special parameters such as the distance between solutions, etc. This paper presents a new approach to Service selection for Service Composition based on QoS and under the user´s constraints. So in this approach, the QoS measures are considered based on the user´s constraints and priorities. The experimental results show the method can achieve the composition effectively and it has a lot of potentiality for being applied.