Exclusive Gateway

Exclusive Gateway
A diverging Exclusive Gateway (Decision) is used to create alternative paths within a Process flow. This is basically the "diversion point in the road" for a Process. For a given instance of the Process, only one of the paths can be taken.
— BPMN 2.0.2 Standard, 10.6.2, Exclusive Gateway

Exclusive gateways are one of the most common sights within a process model. They are used to model decisions within a process.

To decide which route the process follows, the conditions on the outgoing Sequence Flows are checked. The conditions are modeled as an expression and must always evaluate to a boolean value of true or false. It is important to understand that the conditions of an exclusive gateway are not modeled on the gateway itself but rather on the outgoing sequence flows.

If more than one condition evaluates to true, the path that was defined first is chosen. This should obviously never happen. If no condition evaluates to true, the process is stuck.

There is the possibility to mark a Sequence Flow as Default Flow. If you do so, the flow follows this route if no condition matches.

Example

The following example shows how an Exclusive gateway is used to model a simple decision.

Exclusive gateway

Attributes

Group Attribute Description

General

ID

The unique identifier of the element within the process model.

Name

The name of the element. This is the name displayed in the diagram.

Security policy

The security policy associated with this element.

Documentation

A description and additional information about this element.

Details

Asynchronous

When enabled, the activity is started as an asynchronous job. The process state is persisted before this element is executed. Then the process execution is resumed asynchroneously. This can be used when the execution of an activity takes a long time to return the user interface. However, if an error occurs before the following wait state, there is no direct user feedback.

Flow order

The order in which the outgoing flows are evaluated and stored in the XML representation of the process. The order of the outgoing flows is managed by clicking on the up and down arrows icon.

Visual

Font weight

The font weight of the element in the diagram.

Font size

The font size of the element in the diagram.

Font color

The font color of the element in the diagram.

Font style

The font style of the element in the diagram.

Background color

The background color of the element in the diagram.

Border color

The border color of the element in the diagram.