Minimum Unsatisfiability based QoS Web Service Composition over the Cloud Computing

Cloud Computing based Software as a Service (SaaS) combines multiple Web Services in order to satisfy a SaaS request. SaaS is based on Service Oriented Architectures and Web Service technology which are popular paradigm to design new generation of applications. These functionalities are published on the Internet, but exploiting rigorously a large data stream in order to use Web Services is a complicated and laborious task which may involve error prone. In this paper we investigate the problem of SaaS Web Service Composition. We present a new technique that combines an encoding into SAT and a Minimal Unsatisfiability Subformulas extraction to obtain the minimum SaaS Web Service Composition. Furthermore, we generalize this approach to take into account the quality of SaaS Web Service.