The elements · 05 · 9 min
Events
Circles. Two independent questions decide the symbol: when in the flow, and what kind of trigger.
The border tells you when
A thin single border is a start event: it creates the token and has no incoming sequence flow. A double border is intermediate: it happens during the flow, or sits on an activity’s boundary. A thick single border is an end event: it consumes the token and has no outgoing sequence flow.
The fill tells you catching or throwing
An unfilled marker catches: the process waits for something. A filled marker throws: the process emits something and carries on. Start events always catch; end events always throw.
Lab · Event matrixall BPMN 2.0 events · click a cell for details · faded = not possible
| Start | Intermediate | End | ||||||
|---|---|---|---|---|---|---|---|---|
| Top level | Event sub-process | Event sub-process, non-interrupting | Catching | Boundary | Boundary, non-interrupting | Throwing | End | |
| None | ||||||||
| Message | ||||||||
| Timer | ||||||||
| Error | ||||||||
| Escalation | ||||||||
| Cancel | ||||||||
| Compensation | ||||||||
| Conditional | ||||||||
| Link | ||||||||
| Signal | ||||||||
| Terminate | ||||||||
| Multiple | ||||||||
| Parallel multiple | ||||||||
After this module you can
- Read border weight to tell start, intermediate and end apart
- Read marker fill to tell catching from throwing
- Know which event type and position combinations are allowed