Good and Bad Excuses for Unstructured Business Process Models

Building well-structured business process models (similar to writing well-structured controlflow blocks in a programming language) is often recommended in order to raise the quality and readability of such models. This article discusses patterns that are related to structured and unstructured business process models. One kind of these patterns deals with situations where some part of the model is modelled in an unstructured way. For these patterns, possible structured alternatives for improving the model are given. Another kind of patterns deals with situations where an unstructured modell is the best way to express some situation. We illustrate this by discussing one pattern of both types. Finally, we give an example of a pattern for which the decision whether an unstructured model should be changed into a wellstructured one needs a closer look at the purpose of the model.