Service Selection Algorithm of Two-layer QoS Model based on Functional Grouping

With the development and application of service computing technology,Quality of Service has become one of the important basis for the selection of web services in service composition. In order to avoid the influence of functional difference of services on the Qos of services in the service compositon, this paper proposes a two-layer QoS model service selection algorithm based on feature grouping. First of all, in the process of service composition, the services are grouped according to their function, then the services in the same group are further grouped by Qos, which includes common Qos and reputation degree QoS based on the subjective and objective factors. The reliability of service is defined to express the common Qos, while a kind of evaluation method of reputation degree is raised to express the reputation degree Qos. Experimental results show that this method can obtain web services with high reliability and high credit standing, meanwhile it can increase the success rate of web service composition.