Constraints-based response time for efficient QoS in Web Services Composition

Web Services Composition (WSC) is a paradigm for enabling application integration within and across organizational boundaries. Nowadays, the Quality of Service (QoS) that WSC should offer becomes a priority for service providers and an exigence for customers. Therefore, the response time of a web services composition is a crucial problem. However, previous works proposed only analytical formulas with respect to response times of few BPEL constructors. They do not provide any mechanisms or tool in order to analyze and verify the time constraints. In this paper, we propose a Framework called QoS4WSC that is able to evaluate constraints-based response time in WSC. In order to provide a model for estimating the effective response time of a service composition, we use a parsing file composition technique. Since elementary web services is based on a best effort approach, we propose a new architecture which takes into account the response time of a given service. Our architecture is composed by two components. The first one pre-determines the response time of elementary web services and the second one verifies the QoS constraints of WSC.