I was surprised to find this piece on ebizQ, covering the "emerging star of business process modeling", BPMN 2.0.? BPM and BPMN get a lot of coverage in the forums on ebizQ, but don't as often show up as topics for articles (at least, that hit my radar screen).?? Of particular note is Jon Siegel's concise separation of three key business process concepts: conversation, orchestration, and choreography:
The underlying idea is that "a set of processes form choreography if they communicate and there is no overarching process in charge of it," explains Jon Siegel, OMG's vice president for technology transfer. He says BPMN is fantastic at modeling, but the addition of choreography represents a major step forward in version 2.0. He says choreography was inserted belatedly because BPMN was first designed and came into widespread use a time when there wasn?t as much Internet-based commerce and choreographic processes were unusual, if they happened at all.
In contrast, Siegel says, "orchestration" is the BPMN word for conduct of a process internal to a business entity. "These days, a substantial fraction of e-commerce is choreography-based rather than conversation-based or orchestration-based," he notes. "So the language had to be upgraded to take this into account, particularly for business users to help them to model their systems."
I don't think I've seen such a concise description, if you just take the first sentence of the first paragraph, and then the second paragraph, that neatly puts each type of interaction in its place.