Five techniques, five functions
Continuous improvement is not a tool, it is a routine. To sustain it, each technique serves a different function: keeping the rhythm, structuring the cycle, finding the cause, communicating, and going to see. Confusing the functions leads to using the wrong tool for the problem.
The five techniques below form a lean, complementary set. Competitive advantage does not come from knowing the list, but from keeping the cycle turning every week, with leadership present and the teams involved. Your competitors know the tools too. What they cannot copy is the discipline of the routine.
1. Kaizen: the culture of small improvements
Kaizen is the practice of improving a little every day, with the participation of the people who do the work. It works as a routine or as a focused event lasting a few days.
When to use it: to build the habit, address small and frequent problems, and involve the teams. Limit: on its own, it can turn into a list of loose ideas with no focus on the company's objective.
Usage example: a board in the cell where any operator can log an idea, the supervisor decides within a week, and the simple ones are implemented with the name of the person who suggested them.
2. PDCA: the learning cycle
PDCA has four steps: plan, do, check, and act. It ensures that a change is tested, measured, and standardized.
When to use it: whenever you are going to test a change. It is the backbone of the other techniques. Limit: if the "check" step is skipped, it becomes just action without learning.
Usage example: test a new tool layout on one shift, measure cycle time before and after, and only then standardize it for the other shifts.
3. 5 Whys: the root cause
Ask "why?" repeatedly until you reach a cause that can be eliminated. See 5 Whys.
When to use it: problems with a simple, linear cause, such as a repetitive machine failure or a process error. Limit: for complex problems with several causes, complement it with Ishikawa and data.
Usage example: the machine stopped. Why did it stop? The fuse blew. Why did it blow? There was an overload. Why was there an overload? The bearing seized. Why did it seize? It lacked lubrication. Why was it not lubricated? The maintenance plan did not include that point. The action is to fix the plan, not just replace the fuse.
4. A3 report: thinking and communicating on one sheet
The A3 brings together on one sheet the context, current situation, target, root cause analysis, countermeasures, and follow-up. It forces the author to be clear and makes the conversation with the manager easier.
When to use it: problems that require a decision or alignment across areas. Limit: it takes time; it is not worth it for quick fixes.
Usage example: recurring complaints about late shipments, which involve planning, production, and logistics, and call for a single shared analysis with defined owners.
5. Gemba walk: going to see the real process
The gemba walk is the manager's walk to the place where the work is done, to observe, ask, and learn. It replaces reports with facts that were seen.
When to use it: as a weekly leadership routine and before defining any solution. Limit: without feedback to the teams, the walk turns into surveillance.
Usage example: every Tuesday, 30 minutes in a different area, with two fixed questions: what gets in the way of your work, and what would you change?
Comparison and how to combine them
| Technique | Main function | When to use | Effort |
|---|---|---|---|
| Kaizen | Build the habit of improving | Routine and focused events | Low to medium |
| PDCA | Structure the test cycle | Every change | Low |
| 5 Whys | Find the root cause | Simple, linear problem | Low |
| A3 report | Think and communicate | Problem that requires a decision | Medium to high |
| Gemba walk | See the facts | Leadership routine | Low |
A simple sequence for combining them:
- A weekly gemba walk reveals the problem.
- Prioritize it and open an A3 if the topic is significant.
- Inside the A3, use 5 Whys to find the root cause.
- Test the countermeasure with PDCA.
- Once the solution is standardized, ongoing kaizen keeps the rhythm going and looks for the next step.
This way, each technique plays its role and none is used beyond its function. The chain also makes clear what each person does: the leader goes to the gemba and prioritizes, the team analyzes and tests, and everyone standardizes what worked. For the step-by-step of kaizen in production, see kaizen in practice.
Next step
Start with the simplest one: schedule a weekly 30-minute walk at the gemba, write down three problems, and choose one for a short PDCA. After a month, assess whether it is worth opening the first A3. Keep the rhythm with short, regular stand-up meetings in front of the board, always with the same questions: what did we do, what did we learn, what comes next. Record the learning on the visual management board.
Avoid the mistake of adopting all five at once. Each technique needs an owner and a routine. Start with the one that solves the most visible pain and leave the others until the routine is firm. Introducing one per month, in this order, gives the team time to absorb the method and gives leadership time to show consistency. Competitiveness comes from the accumulation of small standardized gains, not from one big isolated project.
Frequently asked questions
What are the 5 continuous improvement techniques in this article?
Kaizen, PDCA, 5 Whys, the A3 report, and the gemba walk. Each has a distinct function and they complement one another.
Which technique should I start with?
The gemba walk and PDCA, which are simple and build the habit of observing and testing before moving on to heavier tools.
What is the difference between PDCA and A3?
PDCA is the test cycle. The A3 is a one-sheet format that documents the reasoning, usually following the PDCA logic.
Do the 5 Whys solve any problem?
No. They work well for simple causes. For complex problems, combine them with Ishikawa and data analysis.
Does kaizen need a lot of investment?
No. The focus is on small, low-cost improvements made by the people who do the work.
Keep studying
Sources
- LIKER, J. O Modelo Toyota. Porto Alegre: Bookman.
- ROTHER, M.; SHOOK, J. Aprendendo a Enxergar. São Paulo: Lean Institute Brasil.
- Lean Enterprise Institute. Lean Lexicon: A3 Report. https://www.lean.org/lexicon-terms/a3-report/
- Lean Enterprise Institute. Lean Lexicon: Kaizen. https://www.lean.org/lexicon-terms/kaizen/
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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.
