Automated Web Service Composition has gained a significant momentum in facilitating fast and efficient formation of business-to-business collaborations where an important objective is the utilization of existing services to respond to new business requirements in a timely manner. In this context, the service delegation problem can be formulated as follows: When a user poses a sequence of requests to a "service community", how to delegate the requests to the available services registered in the community so that the user requests are satisfied via a collaboration of these services. Here, we present a formal analysis of the constrained service delegation problem where users also provides a set of quality constraints about the delegation of their requests. We follow the "Roman" service composition framework and extend it with a QoS model. We use the Presburger arithmetic to specify constraints. We show that there exists a linear time algorithm for the service delegati...
Oscar H. Ibarra, Bala Ravikumar, Cagdas Evren Gere