Exclusive gateways are represented with this shape:
An exclusive gateway evaluates the state of the business process and, based on the condition, breaks the flow into one of the two or more mutually exclusive paths.
In the example below, an exclusive gateway requires that the mode of transportation be evaluated. In this case, one light will be placed in the Old North Church if the British attack by land, two if by sea.
Event-based gateways are represented with this shape:
An event-based gateway is similar to an exclusive gateway because both involve one path in the flow. In the case of an event-based gateway, however, you evaluate which event has occurred, not which condition has been met.
An example of an event-based gateway is the decision to hold fire until your soldiers can see the whites of their enemies' eyes. In this process flow, if a certain amount of time passes without the British coming, the soldiers will go home.
Parallel gateways are represented with this shape:
A parallel gateway is very different than the previous gateways because you don't evaluate any condition or event. Instead, a parallel gateway is used to represent two concurrent tasks in a business flow. It is the same as a fork in a UML activity diagram.
In the example below, this business process uses a parallel gateway because the company is having its cake and eating it too.
Parallel event-based gateway
Parallel event-based gateways are represented with this shape:
As the name suggests, this gateway is similar to a parallel gateway. It allows for multiple processes to happen at the same time, but unlike the parallel gateway, the processes depend on specific events. You can think of a parallel event-based gateway as a non-exclusive, event-based gateway where multiple events can trigger multiple processes, but the processes are still dependent upon specific events.
Inclusive gateways are represented with this shape:
An inclusive gateway breaks the process flow into one or more flows. The example below shows an inclusive gateway that triggers different processes based on the way customers responded to a product survey. If the customer is satisfied with A, they are added to the Product A email list. If the customer is satisfied with B, they are added to the Product B email list. And if the customer is not satisfied with A, they are sent a voucher.
Complex gateways are represented with this shape:
As the name signifies, complex gateways are only used for the most complex flows in the business process. They use words in place of symbols and, therefore, require more descriptive text. Use the complex gateway if you need multiple gateways to describe the business flow; otherwise, you should use a simpler gateway.