Policy-Based Service Composition and Recommendation
Rolv Bræk, Humberto Nicolás Castejón, Hien Nam Le, Judith E. Y. Rossebø · IGI Global eBooks · 2010
This chapter addresses concepts and methods to support dynamic composition of situated services. We focus mainly on service modelling and service design for execution environments that can support dynamic composition of situated services. In our approach, services are modelled using UML 2.x collaborations that are mapped to parts of a UML 2.x design model. Services are also associated with situations, that is, sets of properties that characterise the executing environment of the service. A policy-driven mechanism is proposed to enhance the service composition process. The policy model takes into account context situations and user preferences that can impact the performance and functionalities of the composed services. Within a given situation, executable services are identified and service composition policies used to determine their execution order. We demonstrate the approach using a multi-media over IP service that takes into account security requirements, monitored threat levels, user locations and preferences.