The increased interest in a more disciplined approach for Business Process Management has motivated many organizations to make significant investments in process modelling initiatives. This, in turn, has triggered significant related research. One outcome of this development is the Business Process Modeling Notation (BPMN), which has been proposed as the new process modelling industry standard. BPMN has become over the last two years a popular process modelling technique. This paper represents the first contribution towards a theoretically sound and empirically validated analysis of BPMN. Based on an established process, we conducted a representational analysis of BPMN using a representation model based on the Bunge ontology. In addition to the theoretical identification of possible shortcomings of BPMN, we conducted a comprehensive series of interviews with BPMN users in order to seek empirical evidence for our propositions. Through this study, we identified a number of critical issues related to the practice of modelling with BPMN in contemporary process management initiatives, for example, the capture of business rules and the specification of the Lane and the Pool constructs.