Formalising Web Services

Despite the popularity of web services, creating them manually is an intricate task. Composite web services are defined using the evolving standard for BPEL (Business Process Execution Logic). It is explained how CRESS (Chisel Representation Employing Systematic Specification) has been extended to meet the challenge of graphically and formally describing web services. Sample CRESS descriptions are presented of web services. These are automatically translated into LOTOS, permitting rigorous analysis and automated validation