I haven't found the answer to this question anywhere: does SAP BPM have choreography diagrams support or not? As well as collaboration and conversation ones.
The differences are thoroughly explained here http://blog.goodelearning.com/bpmn/conversation-vs-collaboration-vs-choreography/
To speak in greater detail, does SAP BPM engine support such elements as Choreography task, Global Choreography Task, Sub-Choreography and etc.
If not, how can we implement more complex BPMN models in SAP BPM?