Efficient QoS Aggregation in Service Value Networks

In recent years, the trend towards standardization, simplification and modularization in the service sector has fostered the raise of Service Value Networks where providers and consumers jointly co-create value. With many different competing services available, the user experience, which is captured by the non-functional Quality-of-Service (QoS) attributes, is an important competitive factor. QoS computation for complex Web services, i.e. the aggregation of QoS factors from atomic services, is essential for an automated an optimized Web service selection process. However, the computational complexity of QoS aggregation has often been disregarded in the respective field of research, whereas computational efficiency is inevitable for the application of optimization approaches in on-line scenarios. The threefold contribution of this paper consists of an elaboration on the computational complexity of aggregating QoS, an approximation scheme that allows for a computational efficient optimization and a broad analytical and simulation-based evaluation of this approach.