Universidad de Malaga
Services can be accessed and used to fulfill basic requirements, or can be composed with other services in order to build bigger systems which aim at working out complex tasks. These services must be equipped with rich interfaces to ease their reuse and enable their automatic composition. The authors can distinguish several interoperability levels for the description of service interfaces (i.e., signature, interaction protocol/behaviour, quality of service, and semantics). Composition of services is seldom achieved seamlessly because mismatch may occur at the different interoperability levels and must be solved.