Most business owners only do a post-mortem after something goes wrong. They sit down, review what failed, and figure out what they could have done differently. It is a useful exercise, but it is too late. The money is already gone. The client is already lost. The launch has already flopped.

The pre-mortem flips that on its head. Instead of asking “what went wrong?” after the fact, you ask “what could go wrong?” before you commit. It is one of the simplest, most powerful tools in business strategy, and almost no small business owner uses it.

This guide will walk you through exactly how to run a pre-mortem, when to use it, and how to turn the exercise into real decisions that protect your business.

What Is a Pre-Mortem?

The term was popularized by psychologist Gary Klein, who studied how expert decision-makers anticipate failure. The idea is simple: before you launch a product, sign a contract, hire someone, or make a major investment, you imagine that the project has already failed. Then you work backwards to figure out why.

That shift in framing changes everything. When you ask “will this work?” people tend to be optimistic. When you ask “it already failed — why?” the brain suddenly finds all the risks it glossed over before. It is a psychological trick that bypasses wishful thinking.

For small business owners, this is especially valuable. You are often the most emotionally invested person in the room. A pre-mortem gives you structured permission to think like a critic instead of a cheerleader — before it costs you anything.

When to Run a Pre-Mortem

You do not need a pre-mortem for every small decision. But it earns its place in a few key situations:

• Before a major financial commitment — new equipment, a lease, a big hire
• Before a product or service launch
• Before entering a new market or expanding locations
• Before signing a significant contract
• Before making a key hire — especially a leadership role
• Before a major operational change — new software, restructured team, new supplier

If the decision is reversible and low-stakes, skip the pre-mortem and move fast. If it is the kind of decision that could hurt your business for months or years if it goes sideways, take an hour and run the exercise first.

How to Run a Pre-Mortem: Step by Step

Step 1: Define the Project or Decision

Write down exactly what you are evaluating. Be specific. “We are launching a new service package at $1,500/month targeting local restaurants” is useful. “We are growing the business” is not. The more specific you are, the more useful the pre-mortem will be.

Step 2: Set the Scene — It Has Failed

Tell everyone involved (or yourself, if you are doing this solo): “It is twelve months from now. This project has completely failed. Not just underperformed — failed. We lost money, time, or both. Now let’s figure out why.”

This framing matters. Do not say “what might go wrong.” Say “it went wrong — what happened?” The past tense triggers a different kind of thinking.

Step 3: Generate Failure Reasons Independently

If you have a team, have everyone write down their failure reasons silently and independently before sharing. This prevents groupthink. The loudest voice in the room should not drown out the quietest concern.

If you are doing this solo, give yourself ten to fifteen minutes to write as many failure scenarios as you can. Do not filter. Write everything down, even the things that seem unlikely. You can prioritize later.

Common failure categories to explore:

• Financial — ran out of cash, underestimated costs, revenue never materialized
• Operational — bottlenecks, quality control failures, team overwhelm
• Market — customers did not want it, wrong pricing, wrong timing
• Competitive — a competitor undercut you or launched something better
• People — key hire did not work out, team friction, key person left
• External — economic downturn, supplier failure, regulatory change
• Execution — missed deadlines, scope creep, poor communication

Step 4: Share and Discuss

Go around the room and have everyone share their top failure reasons. Group similar ones. This step often surfaces risks that nobody had consciously articulated — someone knew something was off but never had the right moment to say it. The pre-mortem creates that moment.

Pay special attention to concerns that come from multiple people independently. If three people on your team all worried about cash flow without talking to each other, that is a signal worth taking seriously.

Step 5: Prioritize by Probability and Impact

Not every risk deserves equal attention. After you have your list, sort each item by two factors: how likely is it to happen, and how badly would it hurt if it did?

A simple two-by-two grid works fine here:

• High probability + High impact — these are your priorities. Address them before you proceed.
• Low probability + High impact — have a contingency plan ready.
• High probability + Low impact — monitor and manage, but do not lose sleep.
• Low probability + Low impact — acknowledge and move on.

Step 6: Build Specific Countermeasures

This is where the pre-mortem turns from a thinking exercise into a business tool. For each high-priority risk, decide what you will do about it. You have four options:

• Prevent it — change your plan to eliminate the risk before it can happen
• Reduce it — take steps to lower the probability or the damage
• Transfer it — use a contract, insurance, or partnership to shift the risk to someone else
• Accept it — acknowledge you cannot control it and decide your threshold for walking away

Write these down. A pre-mortem that ends with “we should be careful about cash flow” is worthless. One that ends with “we will not launch until we have three months of runway reserved and a signed contract from our first client” is useful.

A Real-World Example

Say you are a service business owner thinking about hiring your first full-time salesperson. You are excited. You have been the only one selling, and you are ready to hand that off. Before you commit, you run a pre-mortem.

Failure scenario: twelve months from now, the hire did not work out and you are worse off than when you started. Why did it fail?

• You did not have a defined sales process — the rep had nothing to follow
• The base salary put too much pressure on cash flow before they ramped up
• You hired for personality but not for skill fit with your specific sales cycle
• You did not set clear 90-day targets, so neither of you knew if it was working
• The rep sold deals you could not deliver profitably

Now you have a checklist. Before you hire, you document your sales process. You set a performance milestone at 60 days. You define which deals are profitable to close. You structure the comp so base is modest and upside is commission-heavy. You have a better hire and a much better shot at success.

That is the pre-mortem in action. For more on building a strategic framework around your decisions, see How to Use Decision-Making Frameworks to Run a Smarter Small Business and How to Use Scenario Planning to Future-Proof Your Small Business.

Running a Pre-Mortem Solo

Most small business owners do not have a team of five sitting around a whiteboard. That is fine. The pre-mortem still works when you do it alone, but you need to work a little harder to get out of your own head.

A few techniques that help:

• Write it down, do not just think it. Writing forces clarity and slows you down enough to catch things you would skip mentally.
• Talk to one outside person. A mentor, advisor, or trusted peer who has no stake in the outcome can surface blind spots you cannot see yourself.
• Come back to it the next day. Fresh eyes on your own writing often reveal what you glossed over the first time.
• Use the “skeptical investor” frame. Pretend a smart, skeptical investor is reading your plan and looking for reasons to say no. What would they flag?

The Small Business Administration offers free counseling through SCORE and Small Business Development Centers, both of which can serve as outside sounding boards for major decisions.

What a Pre-Mortem Is Not

A pre-mortem is not an excuse to kill every initiative out of fear. Some entrepreneurs use risk thinking as a way to delay action indefinitely. That is not the goal.

The goal is to make better decisions faster. A good pre-mortem does not leave you paralyzed. It leaves you with a cleaner plan, a shorter list of real risks, and specific actions to address the ones that matter. You move forward with your eyes open rather than crossed fingers.

It also is not a substitute for good judgment. If every risk you identify falls into the “low probability, low impact” bucket, that is a sign your plan is solid — not that the exercise is broken. Trust the output.

How to Make Pre-Mortems a Habit

The best small business owners build the pre-mortem into their decision-making process the same way they build in financial review or team check-ins. It does not need to be a formal event every time. A fifteen-minute solo session before a major commitment is enough.

Consider adding it to your standard playbook for any decision above a certain dollar threshold or time commitment. For example: any investment over $5,000, any new hire, any contract lasting more than six months. Set the threshold that fits your business, then stick to it.

Over time, you will start to notice patterns. Maybe your biggest risk category is always financial timing — you move too fast before the revenue is there. Maybe it is people — you hire based on optimism rather than evidence. The pre-mortem teaches you about your own decision-making tendencies, which makes every future decision sharper. This pairs well with the strategic planning process you should already have in place for your business.

The Bottom Line

Most business failures are not surprises in hindsight. The warning signs were there. The pre-mortem is a tool that forces you to look at those warning signs before they become warning shots. It takes an hour. It costs nothing. And it can save you from the kind of mistake that takes years to recover from.

Build it into your process, and you will make better bets, move more confidently, and spend a lot less time cleaning up problems that were avoidable from the start.

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