Modeling Inter-Organizational Workflows ======================================= Sladek, A. and Wolski, A. Proc. Internat. Symposium on Applied Corporate Computing (ISACC'96), Oct. 30 - Nov. 1, 1996, Monterrey, Mexico, pp. 13-22 (Best Paper Award) Abstract Inter-organizational cooperation has many facets. One of them is information system (IS) cooperation which is a process of performing pre-defined cooperative activities using computer technology. IS cooperation can be modeled and implemented in the form of inter-organizational workflows involving (typically) pre-existing information systems of the participating organizations. When participating information systems belong to autonomous organizations, they can at any time decide to exercise their autonomy by, for example, refusing to execute their part of the cooperative work. Modeling parallelism, asynchrony and exception handling policies emerge as major challenges. Traditional data and control flow based modeling approaches fail to capture these aspects of IS cooperation. This paper reports on a case study of inter-organizational IS cooperation. A model of a real-world workflow spanning three autonomous organizations is presented together with the discussion of the encountered modeling difficulties and technical implications. Suggestions for improvement in the modeling approach are also included.