Composition and Customization of Web Services Using Wrappers: A Formal Approach Based on CSP

Web services (WSs) compositions deal with specifying how to assemble a complex WS system from elementary services. These services can be provided on the Web by third parties as WSs, COTS, or bespoke components. In many cases, using a component "as-is" is very unlikely to occur. Components which act as building blocks for the construction of WSs have to be customised in particular ways to meet global application requirements before reuse. A component has to be customised because of, for example, incompatibilities between the interfaces of components that need to communicate with one another, need for extra security features, or, blocking unneeded functionality. This paper presents abstractions of methods for WS compositions using Hoare\´s CSP process algebra. These methods enable customisations and reuse of existing components using a powerful technique known as "wrapping".