On Structured Workflow Modelling

Abstract

Recent years have seen the introduction of many commercial workflow management systems. While there are similarities between the languages of various of these systems, there are also significant differences. One particular area of differences is caused by the fact that di erent systems impose different syntactic restrictions. For example, some work ow management systems do not allow the use of arbitrary loops. In such cases, business analysts have to choose between either conforming to the language in their speci cations or transforming these speci cations afterwards. The latter option is preferable as this allows for a separation of concerns. In this paper we investigate to what extent such transformations are possible in the context of various syntactical restrictions (the most restrictive of which will be referred to as structured workflows). We also provide a deep insight into the consequences, particularly in terms of expressive power, of imposing such restrictions