OV-6c Operational Event-Trace Description (BPD) diagram is based on BPMN Process Diagram (BPD). It describes a sequence or flow of activities in an organization that shows how the business work. The diagram shows activities, events, and data that trigger or feed business activities. An OV-6c Operational Event-Trace Description (BPD) diagram is similar to the BPMN Process Diagram (BPD). Some diagram elements have both UPDM and BPMN stereotypes.