Two Kinds of Checklists

Tabbed pilot checklist book for Cessna.

In The Checklist Manifesto, Atul Gawande discovers an interesting distinction among checklists. He divides them into two camps, based on studying airplane pilots.

One type of checklist is called Do-confirm. The other is called Read-do.

Do-Confirm checklists are basically what we call SOP's, Standard Operating Procedures. They are shorter than a full set of instructions — it would be hard to train yourself how to do something if you just read them — but they have sentences and detailed notes. They can be used by an auditor to watch someone performing a task. They can be used by an individual who is managing a series of tasks over a long period of time, checking off boxes as they go. The important point is that Do-Confirm checklists do not work well when a task is very time sensitive.

Read-do checklists are a different species altogether. Read-do checklists are the checklists pilots pull out when, say, an engine blows up while in flight. They are precise and only contain the most critical steps. For pilots, most Read-do checklists are less than ten steps long and some of the steps might be a couple words long, like "Fly plane!" They require an expert to use them because the expert must be able to perform the step without hesitation. The expert must also fill in missing steps — read-do checklists are never 100% complete. They are meant to be used in the moment for short tasks. These checklists are tested over and over in flight simulators to make sure they really work. There is an entire organization devoted to creating and re-testing these checklists so pilots won't refuse them for being too cumbersome. In other words if pilots say "The checklist is too long, it's not useful," the checklist maker considers it a fault of the checklist, not the pilot.

To me, this was a small revelation. A pilot will use both kinds of checklists. But they don't use a lot of Do-confirm SOP's while flying. At that point they use the Read-do checklists -- something very brief, something that doesn't distract them from the task of flying. The Do-confirm SOP is too long, too detailed. They use that before or after they are up in the air.

Pilots would say if you're trying to use a detailed SOP to manage a time-sensitive task —like checking an order or packing a box — chances are people won't use it regularly. It's not because it's broke. It's because it's too cumbersome. The pilot would say you are probably using the wrong kind of checklist — switch to something shorter.