A QoS-Based Web Services Selection Method for Dynamic Web Service Composition

Web services provided a new way of distributed computing that achieve the interoperability between heterogeneous application through platform and language independent interfaces. The creation of value-added services by composition of existing ones is gaining a significant momentum. Since many available Web services provide identical functionality, albeit with different quality of service (QoS), a selection needs to be made to determine which services are to participate in a given composite schema. So,QoS-based dynamic Web services composition has now received much attention. This paper proposed the conception and definition of the compositionly, gave the expression to calculate the single servicepsila and the composition servicepsila compositionly, and added compositionly criterion to QoS model. On this basis, we design a new method to select the services which satifies user from candidate services, which can work better with little time in large number of candidate services.