Event nodes

The event family represents things that occur within a process rather than work that is performed: triggers, signals, timers, messages, and other occurrences. Prefer ACTIVITY for regular work steps and reach for an event only when the emphasis is on the occurrence itself.

Alternative terms you might use: trigger, signal, occurrence.

In BPMN events are drawn as circles. The border style communicates when the event fires within the lifecycle of a process (start, intermediate, or end) and the symbol inside the circle communicates what kind of event it is. Instant Process draws the border from the event's place in the flow:

• An event that only has outgoing links is a start event, drawn with a thin single border.
• An event that only has incoming links is an end event, drawn with a thick border.
• Every other event is an intermediate event, drawn with a double border.

Every event is also a catch event or a throw event. A catch event waits for the occurrence and a throw event causes it. A catch event draws its marker as an outline and a throw event draws its marker filled. The direction follows from the event's type and its border:

• A start event is always a catch event.
• EVENT, EVENT-TIMER and EVENT-CONDITIONAL are catch events with every border.
• EVENT-SIGNAL and EVENT-LINK catch as intermediate events and throw as end events.
• EVENT-ESCALATION, EVENT-COMPENSATION, EVENT-ERROR and EVENT-CANCEL throw as intermediate and end events.
• EVENT-MESSAGE throws as an end event. As an intermediate event it throws when it only sends a message flow and catches when it receives one, does both or has none. A message flow to a pool counts as sent.

Only links written with NEXT count towards an event's place. A message flow or an association does not. The icons on this page show the intermediate border. For the two process boundaries themselves, see Start and End.

Event

The standard event node defines events that occur within a process. A circle with no specific marker, use it when you know an occurrence happens but the trigger type is unspecified or unimportant. It is a catch event with every border.

Input

EVENT 'text input'

Input suggestion

EVENT 'Event' NEXT

EVENT EventNode 'Event' NEXT OtherNode

Icon

Event Message

The message event node defines communication events that occur within a process, a message sent or received. Its BPMN marker is an envelope, denoting the exchange of a message between participants. It throws as an end event. As an intermediate event it throws when it only sends a message flow and catches otherwise.

Input

EVENT-MESSAGE 'text input'

Input suggestion

EVENT-MESSAGE 'Task' NEXT

EVENT-MESSAGE EventNode 'Task' NEXT OtherNode

Icon

Throw icon

Event Timer

The timer event node defines timed events that occur within a process, often depicting a delay between two other nodes. Its BPMN marker is a clock, denoting a time-based trigger: a fixed date, a duration, or a recurring cycle. It is a catch event with every border.

Input

EVENT-TIMER 'text input'

Input suggestion

EVENT-TIMER 'Task' NEXT

EVENT-TIMER EventNode 'Task' NEXT OtherNode

Icon

Event Conditional

The conditional event node defines an event that occurs when being triggered by changing conditions. Its BPMN marker is a lined page, denoting that a business rule or condition is being evaluated. It is a catch event with every border.

Input

EVENT-CONDITIONAL 'text input'

Input suggestion

EVENT-CONDITIONAL 'Task' NEXT

EVENT-CONDITIONAL EventNode 'Task' NEXT OtherNode

Icon

Event Escalation

The escalation event node defines an event that occurs within a process that triggers an escalation, often starting a subprocess or handing control to a higher-level participant. Its BPMN marker is an upward-pointing triangle, denoting the escalation of a situation. It catches as a start event and throws as an intermediate or end event.

Input

EVENT-ESCALATION 'text input'

Input suggestion

EVENT-ESCALATION 'Task' NEXT

EVENT-ESCALATION EventNode 'Task' NEXT OtherNode

Icon

Throw icon

Event Link

The link event node defines a connector within a process that links two sections of the same diagram, allowing the flow to continue without drawing a direct sequence line. Its BPMN marker is an arrow, denoting an off-page or in-page connector. Links are diagram hygiene: they keep large diagrams readable. It catches as a start or intermediate event and throws as an end event.

Input

EVENT-LINK 'text input'

Input suggestion

EVENT-LINK 'Task' NEXT

EVENT-LINK EventNode 'Task' NEXT OtherNode

Icon

Event Error

The error event node defines an event within a process triggered by the occurrence of an error, often interrupting the current activity and redirecting the flow. Its BPMN marker is a lightning bolt, outlined when catching and filled when throwing, denoting a critical fault that disrupts normal flow. It catches as a start event and throws as an intermediate or end event.

Input

EVENT-ERROR 'text input'

Input suggestion

EVENT-ERROR 'Task' NEXT

EVENT-ERROR EventNode 'Task' NEXT OtherNode

Icon

Throw icon

Event Cancel

The cancel event node defines an event within a process that is triggered by a cancellation, typically within a transaction subprocess that has been rolled back. Its BPMN marker is an X, denoting cancellation of a transactional scope. It catches as a start event and throws as an intermediate or end event.

Input

EVENT-CANCEL 'text input'

Input suggestion

EVENT-CANCEL 'Task' NEXT

EVENT-CANCEL EventNode 'Task' NEXT OtherNode

Icon

Throw icon

Event Compensation

The compensation event node defines an event within a process that is triggered by a compensation action, undoing or reversing the effects of a previously completed activity. Its BPMN marker is a pair of left-pointing triangles (rewind symbol), denoting that work is being undone. It catches as a start event and throws as an intermediate or end event.

Input

EVENT-COMPENSATION 'text input'

Input suggestion

EVENT-COMPENSATION 'Task' NEXT

EVENT-COMPENSATION EventNode 'Task' NEXT OtherNode

Icon

Throw icon

Event Signal

The signal event node defines an event within a process that is triggered by a signal, allowing multiple processes or activities to start or react when the signal is sent or received. Its BPMN marker is a triangle, outlined when catching and filled when throwing, denoting a broadcast signal as opposed to a direct message with a single recipient. It catches as a start or intermediate event and throws as an end event.

Input

EVENT-SIGNAL 'text input'

Input suggestion

EVENT-SIGNAL 'Task' NEXT

EVENT-SIGNAL EventNode 'Task' NEXT OtherNode

Icon