Getting Rid of the OR-Join in Business Process Models

In practice, the development of process-aware information systems suffers from a gap between conceptual business process models and executable workflow specifications. Because of this gap, conceptual models are hardly reused as execution templates. In this paper, we address the notorious "OR-join problem" that is partly responsible for this gap. At the conceptual level people frequently use OR-joins. However, given their non-local semantics, OR-joins cannot be mapped easily onto executable languages. In particular, we present a new approach to map a conceptual process model with OR-joins (expressed in terms of an EPC) onto an executable model without OR-joins (expressed in terms of a Petri net). Although we used an EPC process model as a running example, the approach is equally applicable to other process modeling languages that offer OR-joins as (e.g. BPMN). Moreover, the resulting Petri net can be mapped onto other execution languages such as BPEL. All of this has been implemented in the context of the ProM framework.