How to Run a Premortem: Start from "It Already Failed" and Find the Gaps in Your Prep

A premortem asks one question before you run a plan: “This has already failed. Why did it fail?” It takes the postmortem — finding causes after the fact — and moves it to before the start. The causes you find haven’t happened yet, so you can still fix your preparation and prevent them.

It fits work where preparation decides the result. A first webinar, the first week of a new cohort, an interview with a customer you’ve never met — the harder something is to undo once it starts, the more those fifteen minutes beforehand are worth.

Why “it failed,” not “it might fail”

Ask “what could go wrong?” and not much comes out. It’s your own plan, so you don’t see the holes, and what does surface is vague — “we might run short on time.”

Change the tense and that changes. When psychologist Gary Klein introduced the premortem in Harvard Business Review in 2007, he pointed to a 1989 study by Mitchell, Russo, and Pennington: asking people to imagine that an event has already occurred and then explain it increased their ability to correctly identify reasons by 30%, compared with asking what might happen. The effect is called prospective hindsight.

Once failure is treated as settled, your mind stops defending the plan and starts explaining. Instead of “that won’t happen,” you look for “if it did, this is probably why.”

How to do one: fifteen minutes, four steps

Do it after the plan has taken shape and before you run it. Without a plan there is nothing to examine; right before the run there is no time to fix anything.

1. Declare the failure (1 minute). Pick the date it ended and write one sentence. “November 20: the first live week of cohort 3 is over. It went badly.” A concrete date and scene is what unlocks the next step.

2. Write the reasons (5 minutes). Write whatever comes to mind about what happened that day. Don’t filter. Small things, things that were your fault, plain bad luck — all of it. About ten is enough.

3. Choose (3 minutes). From the list, pick the three that are likely, and would hurt if they happened. Try to block everything and the preparation never ends.

4. Move them into your preparation (6 minutes). Turn each chosen reason into one of two things.

• If you can remove it in advance → put it in your materials or sequence. “The mic wasn’t picked up” → a spare earphone mic in materials, and “sound check 30 minutes before start” in the sequence.
• If you can’t remove it → decide what you’ll do when it happens. “Nobody asked a question” → “If five seconds pass with no question, then I raise the three most common questions from the last cohort myself.”

Example: before week one of an online course, cohort 3

Why it failed	Where it went
More than ten people couldn’t find the join link	Sequence: resend the link the evening before and one hour before
Some people couldn’t open the exercise file	Materials: the file in two formats · Sequence: have everyone open it before we start
Part one ran long and hands-on time was cut in half	Response: if part one passes 40 minutes, the remaining slides go out as a handout and we move to the exercise

All three lines are now inside the plan. The worry has become preparation.

Doing it well

• Ask “why” once more. Stop at “we ran out of time” and there’s nothing to fix. Get to “why — I made the materials the night before” and the preparation changes.
• Write the inner reasons too. Outer reasons like equipment and weather come easily, but inner ones — “I was tired and skipped the rehearsal” — bring things down more often.
• For what you can’t remove, use if-then. Decide in advance so you don’t have to judge in the moment. We covered the form in Implementation Intentions.

Common mistakes

• Stopping at the list of reasons. A list only feeds the anxiety. The premortem is done when the reasons have moved into materials, sequence, or responses.
• Trying to block everything. Prepare for all ten and the preparation outgrows the work. Three is enough.
• Doing it before there’s a plan. You can’t picture what failed, so all you get is vague worry.
• Doing it once and throwing it away. If you’ll do the same thing again, the preparation you fixed in this premortem is next time’s starting point.

How it relates to WOOP and to retrospectives

The Obstacle in WOOP mostly asks what inside you gets in the way, and it comes before the plan. A premortem takes a plan you’ve already made and looks for reasons both inside and out. They don’t overlap when used together.

It pairs with the KPT retrospective. A premortem asks “if it failed, why” before you start; a retrospective asks “how did it actually go” after you finish. The Problems from a retrospective are the most reliable material for the next premortem, because they are failures you lived through rather than ones you imagined.

Where the reasons live

What comes out of a premortem scatters into three places: the reasons for failure, the things to pack in advance, and the actions to take in the moment. If those sit apart from the plan, you won’t see them on the day.

fecit, the app we’re building, keeps those places together on one task. The Obstacle field in Analysis asks, “Picture it already gone wrong: what caused it?” What to pack goes in Preparation, and what to do in the moment goes in Response Rules as “when this happens, I do that.”

For work you repeat, you can keep all of this on a template, so the next task starts from the last premortem.

Whatever tool you use, the order is the same. Declare the failure, write the reasons, choose three, and move them into materials, sequence, and responses.