Boundary Events are events that sit attached to to an activity's boundary. These events can have triggers configured to them and can start alternative or additional paths in a process app. 

Boundary Events can be added to any activity such as Tasks, Call Activities or Sub Processes. Depending on which trigger is configured on the boundary event they will be triggered accordingly. A Boundary Event must have a Sequence Flow connected from the event and connected to another process symbol. When the Boundary Event is triggered the process will continue along the connected Sequence Flow.

Add a Boundary Event

  1. Add a Task, Sub Process or Call Activity to your process model

  2. Right-Click on the Activity and in the configuration panel click on the section Boundary Event. This will open a section in the configuration panel where you can pick a trigger

Interrupting and non-interrupting

In the picture above all Boundary Events are set to be Interrupting. This setting means that when the event is triggered the activity that it is attached to will be canceled and should no longer be done or be available to those who have the task in their inbox and will allow the process to continue along the alternate exception path.

It is possible to make a Boundary Event Non-Interrupting. This setting is done on the Boundary Event and will change the look of the event. A Non-Interrupting Boundary Event can be configured with the same triggers as an interrupting boundary event. However, if the event is triggered the task it is attached will not be canceled. The process will start a parallel alternate exception path but the activities that the Boundary Event was attached to will remain active and available for users to complete as normal.

You can toggle a boundary event to be Interrupting or Non-interrupting by toggling the attribute Cancels activity On or Off. You will immediately see whether or not the Boundary Event is one or the other by the way it looks.

Multiple Boundary Events

It is possible to have more than 1 Boundary Event on an activity. Simply follow the same instruction above when adding a boundary event again to add a second, third or one-hundredth boundary event. Each event can be configured independently and handle several events that start different exception paths giving you as a process app creator many possibilities.


In order for something to happen in your deployed app you need to add a trigger. The following events are supported: