Episode 4 · April 9, 2026 · Hosted by Sebastian
Pools vs. Lanes: When to Separate External Stakeholders
When to use pools and when to use lanes, shown on Susan's sample box process from the course with an external supplier. We modelled it twice, without pools and with a collapsed supplier pool, to show how pools expose the external dependencies you can't optimise away and make supplier reporting and compliance checks possible.
Pools vs. lanes: where your organisation ends and someone else's begins.
The big takeaway
Pools mark organisational boundaries. Lanes mark internal roles.
Mix them up and your diagram says something fundamentally different from what you intended, starting with how much of the process you actually control.
What we walked through
- 01
Pools are organisational boundaries, lanes are internal roles
External parties such as suppliers, customers and partners are separate pools. Internal departments are lanes inside the same pool.
- 02
Why it matters for control and ownership
We modelled Susan's sample box process from the course two ways: first without pools, then with a collapsed supplier pool and message events. Without pools, the diagram implies 100% control. With pools, you immediately see the external dependencies you can't optimise away.
- 03
Collapsed pools as the default
You don't need to model the supplier's internal process. You care about what you send and what you receive. Keep it collapsed unless you have an exclusive relationship where you dictate their process.
- 04
The reporting and compliance angle
When modelled correctly, you can scan your entire process landscape for every supplier interaction. Processes without proper pool boundaries fall through the cracks. The same goes for compliance: supplier data exchange is always the more sensitive piece.
- 05
Internal communication doesn't need message events
A sequence flow crossing a lane boundary already implies a handover. No extra tasks or message events are needed between departments.
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