A gateway is used to model decisions, merges, forks, and joins on a BPMN Business Process diagram. A Decision can be thought of as a question that is asked at a point in the Process Flow. The question has a defined set of alternative answers, which are in effect Gates.

You can set the stereotype of a gateway, and thus change the logic specified by the decision point. You can use gateways to specify all types of business process Sequence Flow behavior, as follows:

You can model data-based decisions and merges, and event-based decisions. In general, exclusive means only one output (for example, one or the other but not both).

You model OR-joins. In general, inclusive means more than one output for a decision (for example, one or the other or both).

You model complex decisions and merging.

You model AND-splits (for forking) and AND-joins (for joining).

See also Gateway definitions.