Modeling and enactment of workflow systems

Abstract

Petri net models and variants thereof have primarily been used to model structured systems such as computer programs, factory production lines, and engineering hardware, in contrast, this paper discusses the issues and challenges in the modeling of human activity in the workplace. This type of activity frequently has a large component that is unstructured, creative work. It is dynamic and difficult to capture via traditional Petri nets. Our research group at the University of Colorado has been investigating Information Control Nets (ICNs), derived from high level Petri nets, as a tool for modeling office workflow. After carefully explaining the notion of Workflow, this paper presents a formal (and also an informal) definition of ICN. We illustrate the utility of ICNs via an office analysis example. Besides being a tool for workflow analysis, ICNs have been used as the basis for the implementation and use of office work coordination systems. These systems provide a computer network based environment to help coordinate, monitor, schedule, and assist in the execution of office work items. To succeed in realistic organizational environments, these systems must be reliable, robust, easy to use, and flexible. Organizational flexibility demands a capability for dynamic change and exception handling. We introduce a mechanism for dynamic change and exception handling in the latter part of the paper. We conclude the paper with a summary, and discussion of some research challenges that we feel must be met for the successful implementation of future generations of workflow systems.