Risk-Sensitive Querying for Adapting Web Service Compositions

Environments in which Web service compositions (WSCs) operate are often dynamic. To remain optimal, WSCs must adapt to the inherent changes that are present in dynamic environments. While previous WSC adaptation methods have yielded promising results, they fail to accomodate the risk preferences introduced by process designers. Risk preferences may influence which Web services are assembled and selected for execution in WSCs and thus must be considered in adaptation. Previously, the value of changed information (VOC) had been proposed to select those services for querying whose revised information is expected to bring about the most change in the composition. In this paper, we enhance VOC so that risk preferences are considered. We augment our previous model so that generalized utility functions (modeling different risk preferences) may integrated into standard value functions that determine optimal Web services to be used in the WSC. We demonstrate that our choice of which WS to query as prescribed by VOC may change if we consider risk preferences as well.