FOCLASA 2006 Configurations of Web Services

The quest for sound foundations for the orchestration of web services is still open. To a great extent its relevance comes from the possibility of defining formal se-mantics for new language standards (like BPEL4WS or WS-CDL) in this emerging and challenging technology. As a step in that direction, this paper resorts to a notion of configuration, developed by the authors in the context of a Reo-like exogenous coor-dination model for software components, to formally express service orchestration. The latter is regarded as involving both the architectural assembly of independent services and the description of their interactions