Sohrabi A thesis submitted in conformity with the requirements

Customizing the Composition of Web Services and Beyond Shirin Sohrabi Doctor of Philosophy Graduate Department of Computer Science University of Toronto 2012 Web services provide a standardized means of publishing diverse, distributed applications. Increasingly, corporations are providing services or programs within and between organizations either on corporate intranets or on the cloud. Many of these services can be composed together, ideally automatically, to provide value-added service. Automated Web service composition is an example of such automation where given a specification of an objective to be realized and some knowledge of the state of the world, the problem is to automatically select, integrate, and invoke multiple services to achieve the specified objective. A popular approach to the Web service composition problem is to conceive it as an Artificial Intelligence planning task. This enables us to bring to bear many of the theoretical and computational advances in reasoning about actions to the task of Web service composition. However, Web service composition goes far beyond the reaches of classical planning, presenting a number of interesting challenges relevant to a large body of problems related to the composition of actions, programs, and services. Among these, an important challenge is generating not only a composition, but a high-quality composition tailored to user preferences. In this thesis, we present an approach to the Web service composition problem with a particular focus on the customization of compositions. We claim that there is a correspondence between generating a customized composition of Web services and non-classical Artificial Intelligence planning where the objective of the planning problem is specified as a form of control knowledge, such as a workflow or template, together with a set of constraints to be optimized or enforced. We further claim that techniques in (preference-based) planning can provide a