Abstract

In the Business Process Modeling Notation (BPMN) and in similar notations, a process model is composed of nodes (e.g. tasks, events, gateways) connected by directed arcs. Although these notations allow process models to have almost any topology, it is often preferable that process models follow some structure. In this respect, a well-known property of process models is that of well-structuredness, meaning that for every node with multiple outgoing arcs (a split) there is a corresponding node with multiple incoming arcs (a join), such that the set of nodes between the split and the join form a single-entry-single-exit region. In other words, a well-structured process model is composed of nested blocks.Many process models found in practice are not well-structured, and it is not always feasible or even desirable to restrict process modelers to produce only well-structured models. An alternative to forcing modelers to produce well-structured process models, is to automatically transform unstructured models into well-structured ones. This talk will present a characterization of the class of unstructured process models that can be transformed into an equivalent structured model, as well as a complete transformation method.