How to Make Better Decisions Using a Pre Mortem

Before you commit to a plan, imagine it has already failed. Then ask why.

The answers may feel uncomfortable, but they can save you from making the same mistakes in real life. This simple exercise is called a pre-mortem, and it helps you see problems that normal planning often misses.

What is a pre-mortem?

A post-mortem happens after something goes wrong. People look back and ask, “What caused the failure?”

A pre-mortem does the same thing before the work begins.

You choose a plan, then imagine that it is one year later and everything has gone badly. Instead of asking whether the plan will succeed, you ask why it failed.

Use this prompt:

It is one year from now. This plan has failed. What went wrong?

This small change helps your brain think in a different way. When you are trying to predict success, you may focus on hope and excitement. When you imagine a failure that has already happened, your brain becomes better at finding possible causes.

Research by Deborah Mitchell, Jay Russo, and Paul Schoemaker found that this method helped people find about 30 percent more reasons for a possible outcome than normal planning did.

The startup that found three hidden problems

A startup team was preparing to launch a new product. Everyone felt hopeful. The plan looked strong, and the team was ready to move forward.

Before the launch, they ran a pre-mortem.

They imagined it was six months later and the product had reached less than 20 percent of the expected customers. Each person wrote down the reasons alone before anyone spoke in the group.

When they compared their answers, three problems appeared:

• The product was difficult to connect with the main platform customers already used.
• The pricing options confused the target buyers.
• The launch date was too close to a major competitor’s yearly event.

None of these problems appeared in the original plan.

The team changed the launch date, made the pricing page easier to understand, and prepared another way to connect the product with the main platform.

Six months later, two of the three problems happened. The team was ready because they had already thought about them.

Why this works

Normal planning often starts with the question, “How can this succeed?” That question is useful, but it can also make people ignore warning signs.

Once a team likes a plan, people may protect it. They focus on reasons it will work and quietly push away doubts. This is especially common when the group is excited, under pressure, or afraid of looking negative.

A pre-mortem gives people permission to talk about problems. They are not saying the plan is bad. They are simply imagining what could go wrong.

The brain also explains past events more easily than it predicts future ones. When you imagine that the failure has already happened, possible causes come to mind more naturally.

That is why the method can uncover risks that ordinary forecasting misses.

How to run a useful pre-mortem

1. Choose the plan first

A pre-mortem works best after you have chosen a plan but before you fully commit to it.

If you do it too early, there may be nothing clear to examine. If you do it after the decision is already locked, people may be too attached to change anything.

2. Imagine a clear failure

Give the group a time frame.

You might say:

It is twelve months from now. The project has failed. What happened?

Be specific about the failure. Did the project go over budget? Did customers refuse to use it? Did the team miss the deadline?

A clear picture helps people find clear reasons.

3. Write alone first

Ask everyone to write down their ideas before the group discussion begins.

This matters because the first person who speaks can shape the whole conversation. Others may simply agree with that person, even when they had different concerns.

Writing alone gives quiet people room to think. It also makes it easier to share an uncomfortable idea.

4. Sort the risks

After collecting the answers, divide the risks into two groups:

Spend your time on the first group. You do not need to create a perfect plan for every possible disaster. You need to prepare for the problems that are both serious and manageable.

For each controllable risk, ask:

• How can we reduce the chance of this happening?
• What early warning sign should we watch for?
• What will we do if it happens?
• Who will be responsible for the response?

This turns worry into a plan.

Check the outside view too

People often judge their plan by looking only at the details in front of them. This is called the inside view.

“We have a great team.”

“We are very committed.”

“Our product is different.”

These things may be true, but they do not tell you how similar plans have performed.

The outside view asks a different question:

What happened to other projects like this one?

How long did similar projects take? How often did they go over budget? How many failed to reach their first target?

Looking at these base rates can protect you from overconfidence. Your plan may be special, but it still belongs to a larger group of similar plans.

Use it for personal decisions too

A pre-mortem is not only for businesses and large projects. You can use it before making an important personal choice.

Before moving to a new city, ask:

• It is one year later and the move has gone badly. Why?

Before starting a side business, ask:

• It is twelve months later and the business has failed. What did I ignore?

Before accepting a new job, ask:

• I have been in this role for a year and regret the decision. What happened?

Write your answers honestly. Do not use the exercise to scare yourself out of every decision. Use it to replace blind yaqeen with a clearer picture.

The goal is not to find a reason to quit. The goal is to find the weaknesses while there is still time to fix them.

Your next step

Before your next major decision, spend ten quiet minutes writing this sentence:

It is one year from now. This decision has gone badly. Here is what happened.

Write alone first. Then share your answers with someone you trust. Choose the risks you can control, and create a response for each one.

A little discomfort before you begin can save you a great deal of pain later. That is the real value of a pre-mortem. It helps you meet failure in your imagination, while you still have the himmat and time to change the plan.

The cheapest failure is the one you have in your head before you’ve spent a dollar in the world.