Abstract (EN)

Web services are "self-contained, self-describing modular applications that can be published, located, and invoked across the Web". They are based on a set of independent open platform standards to reach a high level of acceptance. Web services framework is divided into three areas: communication protocol, service description, and service discovery and specifications are being developed for each one. More and more, users want to deal with complex applications controlled by an explicit process model. Most of specifications languages (WSFL, XLANG, BPEL4WS) propose a set of operators in order to describe the service in a modular way. The basic services are messages driven and the operators are related to the orchestration of activities. In the previous work, we have developed a generic agent capable to fully control the interaction process with a Web service given its specification. This paper presents an alternative approach, which overcomes a limitation of our preceding algorithms, and we briefly describe them. We develop dense time semantics for an XLANG specification. The semantic of a specification is a timed automaton.