Rigorous development of composite grid services

Cress (Communication Representation Employing Systematic Specification) is introduced as notation, a methodology and a toolset for service development. The article focuses on rigorous development of composite grid services, with particular emphasis on the principles behind the methodology. A straightforward graphical notation is used to describe grid services. These are then automatically specified, analysed and implemented. Analysis includes formal verification of desirable service properties, formal validation of test scenarios, testing of implementation functionality, and evaluation of implementation performance. The case study that illustrates the approach is document content analysis to compare two pieces of text. This involves two composite services supported by two partner services. The usability of the service design notation is assessed, and a comparison is made of the approach with similar ones. These show that the Cress approach to developing services is usable and more complete than other comparable approaches.