Definition
A checklist is a short, structured tool — typically five to nine items, runnable in 60 to 90 seconds at a defined moment in a workflow — that lists the routine but high-consequence steps an expert is most likely to drop under load. It is the original safety-engineering invention of aviation (the B-17 pilot's card, 1935) and the central instrument of Atul Gawande's The Checklist Manifesto.
A good checklist is deliberately incomplete. It does not try to spell out everything an expert needs to do; that would be a textbook, not a checklist. It lists only the killer items — the steps catastrophic when missed and historically often missed — and trusts the expert with the rest.
Why it matters
How it works
The instrument has four parts. First, a defined pause-point — a moment in the workflow at which the team must stop and run the list (before anaesthesia, before deploy, before takeoff). Without a pause-point, no list will be run consistently. Second, a type decision: DO-CONFIRM if the work is familiar and the checklist's purpose is verification; READ-DO if the work is unfamiliar or order-critical. Third, content limited to killer items: steps where data or experience shows the failure is catastrophic and the miss is recurrent. Fourth, a verbal, team-run protocol — not paperwork to be silently filled in. The conversation is the point.
The most consequential design decision is not the content. It is who is empowered to call the pause. Aviation borrowed "pilot not flying calls the checklist" from a deliberate dispersal of authority; the WHO surgical checklist hands that authority to the circulating nurse. The structural change in power is at least as important as the list itself.
Common failure modes
- Too long — anything past 60–90 seconds at a single pause-point invites shortcutting.
- Too vague — items like "verify status" with no concrete verification become rubber-stamps.
- Written-only — filling boxes silently captures none of the team-conversation benefit.
- Centrally imposed without local customisation — wording and order must adapt to local practice.
- No iteration — first drafts always fail; the discipline is testing, finding the breakpoints, and revising.