QoS-Aware Web Services Discovery with Trust Management

As the number of available Web services increases, there is a growing demand to find the service that best fits the user’s requirements. Especially, when a set of services fulfilling user’s functional requirements have been discovered, among these services which one will be invoked by the user depends mostly on the Quality of Services (QoS). The problem, however, is that the service providers may have varying levels of quality, and advertised QoS information of Web services is not always valid. In this paper, we propose QoS based discovery and selection of Web services using trust ratings. We adapt OWL-S to describe QoS information for Web services discovery. Services that meet user’s capability and QoS requirements are selected using the service trust rates which are evaluated and assigned by the QoS broker. As the QoS broker manages the trustworthy degree of the service providers, it provides a method to improve the possibility to find services that match user’s QoS and trust requirements. Because we use the reputation by considering feedback from service users, advertised QoS information may be