A Game Logic for Workflows of Non-cooperating Services

A workflow is a collection of coordinated activities designed to achieve a well-defined common goal. Extant research on modeling and analysis of workflows by and large assume that a workflow consists entirely of co-operating tasks that are all controlled by the workflow scheduler. However in real life – especially in the emerging field of Web services, workflows operate in an open environment where some of the tasks they interact with are not under the control of the workflow manager. Indeed, these tasks may be not only non-cooperative but even adversarial. Reasoning about workflows in the presence of such tasks is an unexplored topic. In this paper we develop a framework to reason about them. Our formalism, called Game-CTR, expands our previous work on workflow modeling and reasoning using Concurrent Transaction Logic (CTR) [7] with concepts from Game Theory. We develop a model and proof theory for Game-CTR and demonstrate its applicability for modeling, reasoning, and co-ordinating tasks in workflows that operate in open environments. Game-CTR is a natural generalization of CTR. A pleasant consequence of this generalization is that the results in our previous work [13] emerge as special cases. Contact author : Hasan Davulcu E-mail : [email protected] Phone : (631) 689-1631 Fax : (631) 632-8334 This work was supported in part by NSF grants INT98-09945 and IIS-0072927.