What is the Five Whys technique?

The Five Whys is a root cause analysis technique developed by Sakichi Toyoda and refined within the Toyota Production System. By repeatedly asking 'Why?' — typically five times — you trace a problem back to its fundamental root cause rather than treating its symptoms.

When should you use the Five Whys method?

Use Five Whys when a problem keeps recurring, when current fixes only treat symptoms, or when a team needs to align on the real cause of an issue. It is widely used in lean manufacturing, agile retrospectives, DevOps incident post-mortems, and quality management.

Does Five Whys have to be exactly five questions?

'Five' is a rule of thumb, not a strict limit. You stop asking why when you reach a root cause you can actually act on and fix. This might take three iterations or seven, depending on the complexity of the problem.

What is the difference between Five Whys and a fishbone diagram?

Five Whys follows a single chain of cause-and-effect, making it fast and focused — ideal for straightforward problems. A fishbone diagram (Ishikawa diagram) maps multiple potential causes across categories simultaneously, which suits more complex problems with many possible contributing factors.

Is the FiveWhys tool free to use?

Yes. FiveWhys is completely free, requires no sign-up, and runs entirely in your browser. Your analysis is saved locally in your browser and you can export it as a PNG image or download it as a file.

Five Whys Burgers & Frys

A field guide to running a Five Whys root cause analysis at lunch. Everything you need to know about facilitation, grease management, and why the person who orders the salad should probably not be your timekeeper.

The premise

Here is something the lean manufacturing literature will not tell you: Taiichi Ohno almost certainly ate lunch. Toyota engineers had lunch. Your team has lunch. Somewhere between the invention of the Five Whys and the modern workplace, someone decided that root cause analysis belongs in a windowless conference room at 9 am on a Monday, and that is a tragedy we can correct.

The Five Whys Burgers & Frys session is a structured, 45-minute lunchtime retrospective format built on a simple insight: people think more honestly when they are not hungry, they speak more freely when they are not in a formal setting, and they remember their action items better when those action items were assigned before the chips went cold.

This is a real methodology. It works. It is also an excuse to eat burgers on the company.

What you will need

One problem worth investigating.Not “our culture needs work” — something specific, observable, and recurring. See when to use Five Whys if you are unsure whether yours qualifies.
Three to five people who were closest to the problem. Not the entire department. Not anyone who will spend the session on their laptop. The people who actually know what happened.
Burgers. One per person. Order in advance. A session that starts with a 20-minute debate about where to eat has already failed.
Frys. Shared. This is important. Shared food creates a collaborative atmosphere that individual meals do not. There is no peer-reviewed study on this. There does not need to be.
Something to capture the analysis. A laptop open on the FiveWhys tool works well — one person drives, everyone can see the tree grow. A napkin and a pen also works, though the napkin has a lower export resolution.
45 minutes. Not 30 (too rushed), not 90 (the burgers will be gone and you will still be talking). 45 minutes is the natural duration of a lunchtime Five Whys. Trust the format.

The format, step by step

Step 1 — Order first (5 minutes)

Order before the session starts. This is non-negotiable. Nothing derails a root cause discussion faster than someone arriving late because the app crashed, or spending the first ten minutes of your allocated time choosing between the crispy chicken and the classic smash. Decisions are a finite resource. Do not waste them on the menu.

Designate one person to handle the order. This person is your Logistics Lead. Their contribution to the session is complete. They may now eat in peace.

Step 2 — State the problem while the food arrives (5 minutes)

While you are waiting, the facilitator writes the problem statement where everyone can see it. Resist the urge to start analysing yet. This phase is purely about alignment: does everyone in the room agree on what the problem actually is?

You will be surprised how often the answer is no. Someone thinks you are discussing last Tuesday’s outage. Someone else thinks you are discussing the broader pattern of outages this quarter. These are different problems and they will produce different root causes. Resolve this before the burgers land.

Good problem statement:“The checkout API returned 500 errors for 38 minutes on Tuesday 1 April, affecting approximately 400 orders.”

Bad problem statement:“The system keeps going down.”

Step 3 — The Five Whys (25 minutes)

Food is on the table. This is peak session. Everyone is engaged, nobody is hungry, and the chips are still hot. This is when you do the actual work.

The facilitator asks the first Why. Someone answers. The facilitator captures it in the tool and asks why that happened. And so on. The rules are the same as any Five Whys session, with one additional constraint:

The Burger Rule:you are not permitted to assign blame to a person while holding food. If someone says “because Dave didn’t test it,” they must put their burger down first. This creates just enough friction to discourage it. In practice, nobody puts their burger down, and you stay focused on process rather than people, which is where the useful answers are.

A few facilitation notes specific to the lunchtime format:

Keep the tree visible. If you are using the FiveWhys tool on a laptop, angle the screen so everyone can read it. The visual tree is the shared artefact — it is what prevents two people from simultaneously arguing about different branches of the problem.
The frys are a timer. When the frys are gone, you should be approaching your root cause. If they are gone and you are still on Why 2, something has gone wrong. Either the problem is too complex for this format, or someone is talking too much. In either case, acknowledge it and park the session for a proper room.
Side conversations are fine. A lunchtime session is not a formal meeting. If two people have a quiet sidebar about a specific technical detail, let them. Capture the conclusion and move on. This is one of the genuine advantages of the informal setting — people say things at lunch they would not say in a conference room.
Do not order dessert. This is not a moral position. Dessert extends the session past 45 minutes into ambiguous territory where the analysis is complete but the meeting has not officially ended and someone will definitely reopen a closed point. Dessert is for a different day.

Step 4 — Verify and assign (10 minutes)

You have a root cause. Before anyone leaves, do two things:

First, read the chain backwards. Out loud. Start from the root cause and work back to the problem using “therefore”. If it holds, you have a valid chain. If it sounds absurd when spoken at a lunch table, it was probably absurd in the conference room too — you just did not notice.

Second, assign the corrective action before anyone stands up. Name a person, a deliverable, and a date. Write it down in the tool or, if you used a napkin, photograph the napkin immediately and send it to the group. Napkins have a well-documented tendency to disappear in the bin-clearing aftermath of a meal.

Exporting your session

If you ran the session using the FiveWhys tool, hit Export before you close the laptop. A PNG of the causal tree goes into your incident report, your retrospective notes, or your Slack channel. It takes four seconds and it means the session produced a durable artefact, not just a conversation that half the participants will have forgotten the specifics of by 3 pm.

You can also Save the file and reopen it later if the corrective action needs revisiting. The format is designed for exactly this kind of lightweight follow-up.

Frequently asked questions

Can I run this with pizza instead of burgers?

Yes, with one caveat: pizza by the slice is fine, but a whole pizza requires someone to manage the cutting, and that person will be distracted during the first Why. Order it pre-sliced or assign the cutting to the Logistics Lead before the session begins.

What if we reach the root cause before the food arrives?

This means one of two things: the problem was simpler than you thought (good), or you went too fast and stopped at a symptom (bad). Use the waiting time to stress-test the chain. Ask: if we fixed this root cause, would the problem definitely not recur? If anyone hesitates, keep asking why.

What if we cannot find the root cause in 25 minutes?

Stop. Genuinely — stop. A forced root cause reached under time pressure is worse than no root cause, because it gets written down and treated as fact. Acknowledge that the problem is more complex than the format, book a proper session, and enjoy the rest of lunch. You still made progress: you mapped the first two or three layers of the causal chain and ruled out some candidates. That is not nothing.

Does the session have to be burgers?

No. The session works with any food that does not require significant cutlery interaction, does not produce smells that impair cognitive function, and can be ordered and delivered within the pre-session window. Burgers and frys happen to satisfy all three criteria excellently, and the alliterative branding helps with scheduling adoption. “We’re doing a Burgers & Frys on Thursday” gets more calendar acceptances than “mandatory root cause analysis, 12:30.”

The serious bit at the end

The format is a little silly. The methodology underneath it is not. A 45-minute structured Five Whys session, run consistently after every significant recurring problem, will materially improve the reliability of whatever system you are responsible for. The burgers are a delivery mechanism for getting smart people in a room, fed, and thinking clearly about the same problem at the same time.

That is, not coincidentally, also the definition of a well-run retrospective. Toyota figured this out in the 1950s without the burgers. We just refined the format.

Ready to run your session? Open the FiveWhys tool on a laptop, point it at the table, and start asking why. Open the tool →