A multilevel model for Web service composition

Web services are rapidly becoming popular as a vehicle for the design, integration, composition, and deployment of distributed and heterogeneous software. However, while industry standards for the description, composition, and orchestration of Web services have been under discussion (and development) for quite some time already, their conceptual underpinnings are still in their infancy. Indeed, conceptual models/or service specification are rare so far, as are investigations based on them. This paper presents a multilevel service composition model that perceives service specification as going through several levels of abstraction, from transactional operations to the end user. Importantly, the model allows for specification of desirable composition properties at all levels. Different ways of achieving these properties as well as implications of the model are addressed.