Gateways
Control points that split or merge the flow: exclusive (XOR), parallel (AND), inclusive (OR), event-based and complex.
- Exclusive Gateway
A decision point that routes the flow down exactly ONE of several paths, based on condition evaluation. BPMN's exclusive-or (XOR) split. Diamond, optionally with an X.
- Parallel Gateway
Splits the flow into branches that ALL execute concurrently, and as a join waits for ALL of them — BPMN's AND gateway. Diamond with a plus.
- Inclusive Gateway
Activates EVERY outgoing path whose condition is true — one, several or all — and as a join synchronizes only the paths that were activated. Diamond with a circle.
- Event-Based Gateway
Routes by WHICH EVENT HAPPENS FIRST: the process waits at the gateway, and the first event to occur (message, timer, signal…) chooses the path. Diamond with a pentagon inside a double circle.
- Parallel Event-Based Gateway
A rare start-position variant of the event-based gateway: the process instance is created only after ALL the events following it have occurred. Diamond with a plus inside a double circle.
- Complex Gateway
A gateway for synchronization rules the other gateways can't express — e.g. “continue when 2 of 3 branches complete”. Diamond with an asterisk.