Response time analysis for composite Web services

Service oriented computing (SOC) strives for applications with services as the fundamental items of design, and Web services acting as the enabling technology. Web services use open XML-based standards and are becoming the most important technology for communication between heterogeneous business applications over Internet. In this paper, we focus on mean response times. Thus we propose analytical formulas for mean response times for structured BPEL constructors such as sequence, flow and switch. We propose also a response time formula for multi-choice pattern which is a generalization of switch constructor. Contrarily to previous studies in the literature, we consider that the servers can be heterogeneous and the number of invoked elementary Web services can be variable.