BPMN Pools, Lanes and Message Flows in draw.io
When two organisations work together, BPMN gives each one its own pool and joins them with message flows. Learn how to draw a customer pool and a shop pool with lanes in the free draw.io web app, keep sequence flows inside the pool, and use dashed message flows between pools.
Step by step
Two organisations
- Pools and messages. Your process talks to a customer, but the customer is not part of your company. In BPMN, each organisation gets its own pool, and they talk with message flows. Here's the diagram we'll build in draw.io.
- Blank diagram. Start a blank diagram in draw.io. I've already turned on the BPMN shapes under more shapes.
Pools
- Customer pool. From BPMN general, drag in a swimlane and stretch it wide. This is the customer's pool. We don't model their steps, so we leave it empty. That's called a black box pool.
- Pool with lanes. Now our own pool, with three lanes. Drag in the horizontal pool, make it as wide, and name the pool and each lane after the team that does the work.
Message flows
- Message start. Our process starts when an order message arrives. Drop a message start event, the thin circle with an envelope, into the sales lane.
- Message flow. The order comes from the customer. Click the customer pool, hold control, click the start event, then click message flow. A dashed line means a message between two pools.
Sequence flows
- Tasks in lanes. Finance takes the payment. Drop a task into the finance lane.
- Sequence flow. Connect the start event to it with the blue arrow. That solid line is a sequence flow. It can cross lanes, but it never leaves the pool.
- Tasks in lanes. Then the warehouse packs the order. That task goes in the warehouse lane, under take payment.
- Sequence flow. Connect take payment to pack order.
Message end
- Message end. Once the order is packed, the warehouse emails the tracking number and the process ends. Drop a message end event, the thick circle with a black envelope, next to pack order.
- Sequence flow. Connect pack order to it.
- Message flow. The email goes to the customer. That's another message, so select the end event, control click the customer pool, and click message flow again.
- The finished model. Click away to see the whole model. Solid sequence flows inside our pool, dashed message flows between the pools, and envelopes where a message arrives or leaves.
Recap
- The rules. So, one pool per organisation, lanes for the teams inside it, sequence flows only inside a pool, and message flows only between pools. Subscribe for more draw.io tips for business analysts.
