Lean teams use kaizen because small changes are cheap and quick to test. Over time they add up, and they build a culture where everyone solves problems.
Where it comes from
Kaizen is a core principle of the Toyota Production System. Masaaki Imai's book on kaizen helped popularize the term outside Japan.
At a glance
Small steps, held in place
Swipe sideways to see the whole diagram.
How to apply Kaizen
- 1
Pick a problem worth solving
Choose a specific issue tied to safety, quality, delivery or cost. Keep the scope small enough to act on within days or weeks.
- 2
Go to the gemba
Observe the work where it happens. Talk with the people doing it and gather simple data on the current state.
- 3
Find the root cause
Use five whys or a fishbone diagram to get past symptoms. Agree on the cause before choosing a fix.
- 4
Try a countermeasure
Make a small change and test it quickly. Prefer low-cost ideas the team can implement itself.
- 5
Check results and standardize
Compare results to the baseline. If the change works, update standard work so the gain sticks.
- 6
Share and repeat
Post the improvement on a visible board and recognize the people behind it. Then pick the next problem.
Worked example (illustrative)
A 30-person support team notices that about 22% of tickets are reassigned at least once. An agent suggests a short triage checklist at intake, which the team tests for two weeks on half the queue. Reassignments in the trial half fall to 9% while the other half stays near 21%, so the checklist becomes part of standard work.
Common mistakes
- Collecting ideas in a suggestion box without fast feedback or follow-through.
- Running big kaizen events and skipping the daily, small improvements in between.
- Implementing changes without checking results or updating the standard.
When Kaizen is not the right tool
Kaizen improves an existing process in small steps. When the process itself is wrong, such as a layout that cannot meet demand, a bigger redesign may be needed.
Lean writers call that radical change kaikaku. Kaizen then sustains and refines the new design.
Kaizen meaning
Kaizen is a Japanese word usually translated as "change for the better" or "continuous improvement". In lean it means small, steady improvements made by the people who do the work, every day.
The word is written with two characters. 改 (kai) means change, and 善 (zen) means good. Together they read as a change toward good, which is why the word has no built-in sense of size: a kaizen can be tiny.
Kaizen principles
Most descriptions of kaizen share a few principles. Improvement is everyone's job. Small changes are tested quickly. Problems are treated as chances to learn, not as blame. Facts come from going to the place where the work happens, the gemba.
Standards matter too. A change that works becomes the new standard, so the next improvement starts from a higher base. The continuous improvement page explains the cycle that ties these together.
Kaizen event
A kaizen event, sometimes called a kaizen blitz, is a focused improvement workshop that usually runs for three to five days. A small cross-functional team studies one process, makes changes on the spot and leaves a new standard behind.
Events are useful for problems that need several people at once. Daily kaizen handles the many small fixes in between. Preparation needs a clear scope, a target and current data, and a follow-up after the event checks that the gains held. The kaizen event guide covers the preparation, the agenda and the follow-up.
A month on a daily kaizen board
This example is illustrative. The support team posts ideas on a board with three columns: new ideas, testing and standard.
In one month, the team adds 18 ideas. The team lead reviews new ideas at the daily huddle, so each gets a decision within about 3 days. Eleven are tested, 7 are adopted, and 4 are dropped after the test showed no change.
Two numbers keep the board honest: the days from idea to decision, and the share of tested ideas that were checked against a baseline. If ideas wait weeks for a decision, people stop suggesting them.
Kaizen tools
Kaizen uses the problem-solving tools in this library: PDCA, five whys, fishbone diagrams and A3 reports.
An idea board or kaizen software tracks daily ideas from submission to result.
Guides on this topic
- Kaizen event: meaning, steps and a 3-5 day agendaA kaizen event is a focused workshop that improves one process in 3-5 days. Learn the meaning, roles, agenda, steps, measures and common mistakes.Read the guide
- Lean healthcare: principles, tools and how to startLean healthcare applies lean methodology to patient care. See the principles, hospital wastes, tools, patient flow and how to start in a clinic or ward.Read the guide
- Continuous improvement in lean: examples and strategiesContinuous improvement in lean explained: the PDCA cycle, daily kaizen and kaizen events, with practical examples and strategies that keep improvement going.Read the guide
- Process improvement methodologies: 9 methods comparedProcess improvement methodologies compared: PDCA, lean, kaizen, Six Sigma, TQM, theory of constraints, BPR and retrospectives, with how to choose and combine.Read the guide
Sources
Books and papers show their publication year. Web pages show the month we last checked them.
- 1.Masaaki Imai, Kaizen: The Key to Japan's Competitive Success (McGraw-Hill, 1986)
- 2.Masaaki Imai, Gemba Kaizen: A Commonsense, Low-Cost Approach to Management (McGraw-Hill, 1997)