Service QoS Composition at the Level of Part Names

The cornerstone for the success of Service-Oriented Computing lies in its promise to allow fast and easy composition of services to create added-value applications. Compositions need to be described in terms of their desired functional properties, but the non-functional properties are of paramount importance as well. Inspired by the Web service challenge we propose a new model for describing the Quality of Service (QoS) of a composition which considers the information flow and describes basic service qualities at the granularity level of service part names, that is, operations comprised in service invocation/response messages. In this initial investigation, we overview a number of formal methods techniques that allow to reason with QoS composition based on the proposed model, and propose an algorithm for determining the QoS of a composition given the QoS associated with the individual services.