BPMN processes and pools

n addition to describing the internal process orchestration (or control flow), BPMN can represent choreography (the message exchange between processes). In the real world, an end-to-end business process may be composed of multiple BPMN processes interacting through choreography. A single BPMN process (as opposed to multiple processes) is confined to a pool (i.e. a pool is a container for a BPMN process), is within a single domain of control, and has a start/end (where the process state is changed by a set of activities in the process). The most common reason for multi-pool processes is that an instance of one process does not have one-to-one correspondence with an instance of the other. Unlike traditional process modeling notations, BPMN puts events and exception handling right in the diagram itself, without requiring specification, or even knowledge, of the technical implementation. This business-friendly “abstract” representation combined with precise orchestration semantics lets BPMN process models serve as the foundation of executable process implementations (with implementation properties layered on top of the model, usually be IT).