Organizations use continuous improvement because small changes are cheap, quick and low risk, and because people who do the work see problems that managers miss. Over time the gains compound, and improving becomes part of everyone's job.
Where it comes from
The idea draws on the plan-do-check-act cycle, which W. Edwards Deming built from Walter Shewhart's three-step cycle and later preferred to call plan-do-study-act, and on kaizen at Toyota. Masaaki Imai's 1986 book Kaizen helped spread the term outside Japan.
At a glance
The continuous improvement loop
Swipe sideways to see the whole diagram.
How to apply Continuous improvement
- 1
Set a direction
Agree what matters most right now, such as safety, quality, lead time or cost, and make it visible. Improvement works better when everyone pulls the same way.
- 2
Make problems visible
Use standards, visual boards and daily huddles so gaps between the standard and actual results show up quickly.
- 3
Run small PDCA cycles
For each problem, plan a change, try it on a small scale, check the result against the target and act on what you learned.
- 4
Standardize what works
Update standard work, training and checklists when a change proves itself, so the gain holds and the next cycle starts from a higher base.
- 5
Track and share ideas
Keep a simple log of ideas and their status. Share finished improvements so other teams can copy them.
- 6
Coach the habit
Leaders ask questions rather than hand out answers, and make time each week for teams to improve their own work.
Worked example (illustrative)
A warehouse team adds a five-minute improvement slot to its daily huddle. One week a picker suggests moving the ten fastest-moving items to the front of the aisle. The team tries it for a week, and the average pick route falls from about 140 meters to 110, so it updates the slotting standard. Over the month the slot produces 11 ideas: 4 are tested, 3 become standard and the rest stay in the log. The next idea builds on the new layout.
Common mistakes
- Launching a program with posters and targets but no time set aside for teams to improve their work.
- Collecting ideas faster than the team can test them, so the backlog grows and people stop suggesting.
- Making changes without updating the standard, so gains slide back within weeks.
When Continuous improvement is not the right tool
Continuous improvement assumes the basic process can meet demand. If it cannot, a redesign, sometimes called kaikaku, may come first.
Continuous improvement examples
In a plant, a team cuts a changeover from 40 to 25 minutes over several small trials. In an office, a team removes a duplicate approval from a purchase request. In a clinic, staff move the most-used supplies next to each exam room.
Each change is small, tested and then written into the standard. The continuous improvement in lean guide covers strategies for keeping the habit going across a whole organization.
Continuous improvement, kaizen and kaikaku
The three terms overlap, and people use them in different ways. In lean, kaizen usually means small improvements by the people who do the work, both every day and in focused kaizen events. Continuous improvement is the broader English term. It covers kaizen and also structured projects such as DMAIC.
Kaikaku means radical change: a step change such as a new layout or process, planned and made in one go. A plant might use kaikaku to move from batch production to cells, then kaizen to improve the cells week by week.
Keeping an idea system alive
Most idea systems stall for the reasons in the mistakes above: ideas pile up, nobody answers and people stop suggesting. A few rules help.
Answer every idea within a set time, such as a week, even when the answer is no. Let the team approve small ideas itself, and send up only those that need money or another team. Ask the person with the idea to help test it.
Share results where people can see them, such as a before and after photo on the team board. Count ideas tested and made standard, not ideas submitted, so the system rewards finishing.
| Term | Size of change | Who usually leads it | Example |
|---|---|---|---|
| Continuous improvement | Any size, in steps | Everyone, plus project teams | A DMAIC project or a daily idea |
| Kaizen | Small and frequent | The people who do the work | Moving supplies closer to a station |
| Kaikaku | Large, in one go | Leaders and a project team | Rebuilding a line as cells |
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
- 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
- Lean construction: principles, techniques and how to startLean construction applies lean thinking to building projects. Learn the principles, the eight wastes on site, the Last Planner System and how to start.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
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.Mike Rother, Toyota Kata: Managing People for Improvement, Adaptiveness and Superior Results (McGraw-Hill, 2009)
- 3.W. Edwards Deming, Out of the Crisis (MIT Center for Advanced Engineering Study, 1986)