Starting Processes Multiple Ways in BPMN
Blog: Process Modeling 2.0
In BPMN 2.0, there are several ways to start processes with multiple events. There is a ‘multi-start’ event which looks like this:
Because they are abstract, multiple events can be hard to understand. Generally, a multiple event is “shorthand” notation for multiple events triggering a process. Triggers could include messages, timers, conditions, signals, escalations and other event types.
So, usually when a modeler is working with a requirement to start a process – multiple ways, we suggest the multiple-event gateway. With event based gateways, a path is chosen based on an event. For example, “web form” is a possibility. Also, there could also potentially be no response at all. The Figure below shows an example of handling all three of these events from one gateway.
Multiple events on a event based exclusive gateway
The event-driven exclusive gateway can come in the start of a process, or in a sequence as an intermediate shape. When the gateway is at the start of the process, the event shape inside the diamond is the start multiple start event (single thin line). The figure shows the use of the intermediate, event-driven gateway after an ordinary start of a process. The BPMN2.0 spec also has a starting form with a single thin circle at the center. We end the pattern with a data-based exclusive merge because with the ‘exclusive’ type of the multi-start gateway.
There is also an inclusive form of the event-gateway, but that is the topic for another conversation.