What Is an A3 Report?
An A3 report is a Toyota practice that puts the problem, the analysis, the countermeasures and the action plan on a single sheet of A3 paper, often with graphs. The name comes from the paper size, 297 × 420 mm, close to 11 × 17 inches (tabloid).
At Toyota it became the standard way to solve problems, make proposals and report project status, including value stream mapping. In essence, it is the PDCA cycle told on one page.
The point most often lost outside Toyota: an A3 is not a form. It is a learning process built on dialogue between the person who owns the problem and a leader. The sheet is the record of that thinking.
The most common search is for a ready-made template. A template helps you start, but it does not replace the thinking: what makes an A3 good is the quality of the data, the root cause analysis and the conversation that produced it. That is why this article gives a full worked example, with the math, and not just a blank form.
The Sections of an A3
There is no single format. Authors use between 7 and 9 boxes, so the table below is a practical organization. The left side plans; the right side executes, checks and standardizes.
| Left side (Plan) | Right side (Do, Check, Act) |
|---|---|
| 1. Background: why this problem matters | 5. Proposed countermeasures |
| 2. Current condition, with data and observation | 6. Action plan: what, who, when |
| 3. Goal: what to achieve and by when | 7. Follow-up: indicators and result |
| 4. Root cause analysis | 8. Standardization and next steps |
Order matters. The sheet tells a story from problem to solution, and each box only makes sense if the previous one is solid.
A reading rule helps with reviews: someone who reads only the box titles should understand the story. Someone who reads the content should see the numbers behind each claim. If the goal has no deadline, or the follow-up uses a different indicator from the current condition, the sheet is not ready.
Filled-In Example: Late Deliveries
Illustrative example. A plant shipped 200 orders in the month and 44 reached the customer late. The A3 was built like this.
| Box | Content in the example |
|---|---|
| 1. Background | Late deliveries cause contract penalties and loss of customer trust |
| 2. Current condition | 44 of 200 orders late: 156 ÷ 200 = 78.0% on time |
| 3. Goal | 95% on time in 3 months, meaning at most 10 late orders out of 200 |
| 4. Root cause | Pareto and 5 Whys (see below) |
| 5. Countermeasures | Review the reorder point; cut setup time; name an owner |
| 6. Plan | Purchasing reviews reorder points in week 2; Production cuts setup by week 6 |
| 7. Follow-up | Late orders per week, tracked on a chart |
| 8. Standardization | Monthly reorder point review becomes routine |
First, the data. Classify the 44 late orders by cause and build a Pareto chart.
| Cause of delay | Orders | % of total | Cumulative % |
|---|---|---|---|
| Material shortage | 22 | 50.0% | 50.0% |
| Long setup | 11 | 25.0% | 75.0% |
| Rework | 7 | 15.9% | 90.9% |
| Other | 4 | 9.1% | 100.0% |
Material shortage explains half of the delays. It is the tallest bar and the place to start. Now the 5 Whys:
- Why was the order late? Material was missing on the line.
- Why was it missing? The purchase order went out late.
- Why late? The minimum stock level was out of date.
- Why out of date? Nobody reviews the reorder point when demand changes.
- Why does nobody review it? There is no owner and no routine.
The root cause is not the supplier or the operator. It is the lack of an owner and a routine. The right countermeasure is to assign the review to Purchasing, monthly.
Follow-up after 3 months: 8 late orders out of 200. Calculation: 192 ÷ 200 = 96.0% on time, above the 95% goal. Delays from material shortage fell from 22 to 3. Only then is the change standardized.
Notice how the boxes connect. The 95% goal equals at most 10 late orders out of 200 (5% of 200). The current condition had 44. At least 34 delays had to go, and the material shortage bar, at 22, was not enough on its own: that is why the plan also attacks setup, the second tallest bar. The follow-up uses the same indicator as the current condition, the percentage delivered on time, which makes the before and after comparable.
How to Fill In an A3 Step by Step
- Pick a real, bounded problem. A problem that is too big will not fit on one sheet.
- Go to the place. Observe the current condition with genchi genbutsu, not from the office desk.
- Quantify. Use data for the current condition and a goal with a deadline.
- Analyze the root cause with Pareto, 5 Whys or a cause-and-effect diagram.
- Propose countermeasures tied to causes, not symptoms.
- Set the plan: what, who and when.
- Verify the result with the same indicator as the current condition.
- Standardize what worked and record the learning.
Write by hand, in draft, and redo it after every conversation. The lack of space forces you to summarize. Use simple visuals: a Pareto chart, a process sketch, a photo.
A few writing rules help. Prefer short sentences and action verbs. Show numbers with units and time periods. Replace paragraphs with tables and charts whenever possible. Write the goal in measurable terms, such as "95% on time in 3 months", not "improve deliveries". Name an owner and a date for each action in the plan. An action without an owner and a date is not a plan.
The Three Types of A3
| Type | What it is for | Example |
|---|---|---|
| Problem solving | Understand and remove the cause of an existing problem | The late deliveries above |
| Proposal | Ask for approval of a change or investment | Buying new changeover equipment |
| Status | Report the progress of a project | Tracking an implementation |
The most searched and most used is the problem-solving A3, which follows the logic of the example. All three types use the same one-sheet logic: background, data, analysis, proposal and follow-up. Only the focus changes: fix, convince or inform.
A3 vs 5 Whys, PDCA and DMAIC
| Tool | What it is | When to use it |
|---|---|---|
| 5 Whys | A questioning technique to reach the root cause | A problem with a clear cause chain, on the same shift |
| PDCA | A four-phase improvement cycle | The basis of any continuous improvement |
| A3 | A one-sheet report that uses PDCA and includes the 5 Whys | A bigger problem, several areas, or one that needs approval |
| DMAIC | The five-phase Six Sigma method | Statistical projects to reduce variation |
The tools do not compete. The 5 Whys appear inside the A3, and the A3 is PDCA on paper.
When to Use an A3, and When Not To
Use an A3 when the problem is important, crosses more than one area, has no obvious cause or needs resources and approval. It also works for change proposals, because it forces you to show data and alternatives before asking for a decision.
Do not use it for everything. A misplaced part, a wrong setting or a failure with a short cause chain can be solved with the 5 Whys and an immediate action. Turning every deviation into an A3 creates bureaucracy and wears the method out. A good rule: if the analysis fits in a 15-minute conversation, it does not need a sheet.
The A3 as a Dialogue Between Leader and Learner
The value of the A3 is in the conversation. The leader does not hand over the answer: the leader asks questions, asks for data and sends the author back to the place. The author learns to think lean while solving a problem that matters. Every version of the sheet is discussed and improved.
That is why filling in an A3 alone at the computer, just to meet a requirement, destroys the method. The sheet becomes a report and the learning disappears.
In practice, the conversation follows a simple script. The leader asks: what is the problem, how do you know, what did you see at the place, why does it happen and how will we know it improved. Each unanswered question becomes a task for the next version. After a few rounds, the author starts asking these questions alone, and that is the real goal of the method.
Common Mistakes
- Writing the solution in the current condition box.
- Skipping the visit to the place and filling the sheet with opinion.
- Filling the sheet with tiny text instead of summarizing.
- Proposing countermeasures for symptoms, not the root cause.
- Stopping at the action plan and never completing the follow-up.
- Using an A3 for trivial problems that a 5 Whys would solve.
Next Step
Pick a recurring problem in your area, with a number you can measure. Sketch an A3 sheet in draft with the eight boxes and fill in only the first three: background, current condition and goal. Take it to your leader and ask for questions. Then move on to the cause analysis, one box at a time.
Frequently asked questions
What is an A3 report?
It is a one-sheet A3 report that brings together the problem, the analysis, the countermeasures and the plan, following the PDCA logic.
Why is it called A3?
Because of the paper size it uses, the A3 format (297 × 420 mm).
Who created the A3 report?
Toyota, where it became the standard method for problem solving and planning.
Does the A3 follow PDCA?
Yes. The left side is planning and the right side covers execution, checking and standardizing.
What is the difference between A3 and 5 Whys?
The 5 Whys is a root cause technique. The A3 is the full report, which often includes the 5 Whys in its analysis section.
How many sections does an A3 have?
There is no single number. The most common layout uses 7 to 9 boxes, like the 8 in this article.
Do I have to use real A3 paper?
No. The format forces you to summarize, but what matters is the logic and the dialogue, not the exact paper size.
Who should fill in the A3?
The person who owns the problem, guided by a leader who asks questions and reviews each version.
Sources
- Lean Enterprise Institute. A3 Report. Lean Lexicon. https://www.lean.org/lexicon-terms/a3-report/
- Lean Enterprise Institute. PDCA. Lean Lexicon. https://www.lean.org/lexicon-terms/pdca/
- SOBEK, D. K.; SMALLEY, A. Understanding A3 Thinking: A Critical Component of Toyota's PDCA Management System. New York: Productivity Press, 2008.
- SHOOK, J. Managing to Learn: Using the A3 Management Process. Cambridge: Lean Enterprise Institute, 2008.
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About the author
Lean Manufacturing & Behavioral Management Specialist
Over 20 years in the automotive and metalworking industries (GM and Dana), Lean Manufacturing practitioner since 2006. SENAI instructor and mentor in Brazil’s Brasil Mais Produtivo program, delivering consulting, training and audits for 50+ companies, combining quality, productivity and people development.