A framework for analyzing and testing the performance of software services

Networks "Beyond the 3rd Generation" (B3G) are characterized by mobile and resource-limited devices that communicate through different kinds of network interfaces. Software services deployed in such networks shall adapt themselves according to possible execution contexts and requirement changes. At the same time, software services have to be competitive in terms of the Quality of Service (QoS) provided, or perceived by the end user. The PLASTIC project proposes an integrated model-based solution to the development and maintenance of services deployable over B3G networks. Notably, the PLASTIC solution includes formal techniques that combine predictive and empirical evaluation of QoS-aware services. In this paper we provide an overview of the PLASTIC approach to the assessment of QoS properties. Referring to a complex eHealth service, we first generate and analyze performance models to establish requirements for stand-alone services. Then we use an empirical technique to test the QoS of an orchestration of services even when the actual implementations of the orchestrated services are not available.