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 two translation challenges that are partly responsible for this gap: the notorious 'OR-join problem' and the multiple start events problem. At the conceptual level people frequently use OR-joins. However, given their non-local semantics, OR-joins cannot be mapped easily onto executable languages. Furthermore, conceptual models often have multiple start events while execution languages require a unique start element. In particular, we present a new approach to mapping a conceptual process model with OR-joins and multiple start events (expressed in terms of an EPC) onto an executable model without OR-joins having a single start element (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 modelling languages that offer OR-joins as, for example, 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.