BPMN 2.0 Elements Explained: Events, Activities, Gateways, Flows
BPMN 2.0 has many symbols, but they come in a few families: events, activities, gateways and flows. Draw one example of each in the free bpmn.io modeler, using a library's book loan process, and learn how to read every shape.
Step by step
Four families
- BPMN element families. BPMN looks like a hundred symbols, but they come in four families: events, activities, gateways and flows. Here's the library book loan we'll model, with one example of each, named as we draw it.
Events
- Events. Start a new diagram in bpmn.io. The thin circle is a start event. Events are things that happen. Name it book requested.
Activities
- Activities. Activities are the work people or systems do. Click the start event, then the rounded box in its small menu. That's a task. Check shelf, a verb and a noun.
Flows
- Flows. The solid arrow between them is a sequence flow. It shows the order the work happens in. Follow the arrows and you read the process.
Gateways
- Gateways. Gateways are the diamonds. They split or join paths. Click check shelf, then the diamond. This one is exclusive, so only one path is taken. Ask a question. On shelf? Add the yes path from the gateway: a task, lend book. Label its arrow yes.
- Events. Back to events. Click lend book and add the double circle. That's an intermediate event, something that happens in the middle. Book returned. Click it and add the thick circle. That's an end event, where a path finishes. Name the result. Loan closed.
- Gateways. Now the no path. Drag an end event from the gateway's menu to the space below it. Name it hold placed, and label the arrow no.
- Flows. Flows also link notes. Click check shelf and pick the text annotation from its menu. Type search the catalogue. The dotted line is an association: a note, not a step.
- The finished model. Click away to see the whole model. Three kinds of event, two tasks, one gateway, and solid and dotted flows.
Recap
- The four families. So, circles are events, rounded boxes are activities, diamonds are gateways, and arrows are flows. Solid arrows carry the work, dotted lines carry notes.
