Event Based Gateway

You use an Event Based Gateway when the path the process takes is determined by the occurrence of an event — for example, the receipt of a message by a participant. Use it when the continuation of the process depends on obtaining more data, to wait for a specific time or to meet a condition.

In this example, the condition of the Timer Intermediate Catch Event is set at 5 minutes. If the message arrives before the timer limit, Task A is performed. If the message defined in the Message Intermediate Catch Event doesn’t arrive before the 5-minute limit, Task B is performed.

an Event Based Gateway symbol

When adding an Event Based Gateway to your diagram, know that:

  • It requires two or more outgoing Sequence Flows.

  • Outgoing Sequence Flows must not have a condition expression.

  • Any outgoing Sequence Flows must target either an Intermediate Event] or a Receive Task. You can’t use both.

  • Target elements must not have any additional incoming Sequence Flows.