On Correctness Issues in Conceptual Modelling of Workflows.

Abstract

The conceptual modeling of workflows is the first, and arguably the most important, step towards understanding business processes. A well-defined workflow conceptual model leads to the development of an effective and reliable workflow application. This paper presents a graphical modeling technique for workflows. We introduce four graphical modeling objects: task, condition, synchronizer, and flow. Using the four modeling objects, following workflow modeling constructs are identified: ordering, alternative, exclusive join, concurrency, synchronization, iteration, start/stop, nesting, and contingency. It is possible to easily get into error situations while building large workflow specifications. We present a set of constraints for ensuring the correctness of workflow specifications. The concepts introduced in this paper are applied as a foundation to the development of a CASE tool for the modeling and syntactical verification of workflow graphs.