A process token refers to the current point of execution within a process. Tokens help us figure out how a process works.
- Start events create tokens.
- Tokens follow the sequence flow and pass through activities and gateways.
- Gateways can replicate (split) or synchronize (join) tokens.
- End events consume (destroy) tokens.
- An instance of a process is completed when all tokens are consumed.
If you want to learn more about BPMN tokens, Zbigniew Misiak has written a series of related articles on his BPM Tips blog:
- Token in BPMN
- Exclusive gateways (XOR) and tokens
- Parallel gateways (AND) and tokens
- Inclusive gateways (OR) and tokens
If you want to go really deep, check out Chapter 13: BPMN Execution Semantics in the BPMN 2.0 specification.
