A Taxonomy of Web Services Using CSP

Terms such as conversational and stateless are widely used in the taxonomy of web services. We give formal definitions of these terms using the CSP process algebra. Within this framework we also define the notion of Service-Oriented Architecture. These definitions are then used to prove important scalability properties of stateless services. The use of formalism should allow recent debates, concerning how and whether web services provide standardized access to state, to progress more rigorously.