Exclusive Gateway
Introduction
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.
Properties
:::palette-item com.flowable.design:flowable-core-palette com/flowable/palette/core.process.palette Exclusive_Databased_Gateway