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What is Kaizen?

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Definition​

Kaizen (改善) is a Japanese word meaning "improvement," and it refers to a philosophy and practical methodology that pursues "continuous and incremental improvement." 'Kai (改)' means 'change,' and 'Zen (善)' means 'good,' combining to signify "change for the better." Kaizen is not about pursuing major innovations but rather an approach that accumulates small daily improvements to create significant long-term change.

Kaizen was systematized at Toyota Motor Corporation in Japan after World War II, and management consultant Masaaki Imai introduced it to the world through his 1986 book "Kaizen: The Key to Japan's Competitive Success." Through Kaizen, Toyota grew into one of the world's leading automobile companies, and now Kaizen is applied across all fields beyond manufacturing—including services, healthcare, software development, and personal self-improvement.

The core principle of Kaizen is "There is no perfection. Everything can be improved." Making tomorrow 1% better than today, having everyone on the ground participate in improvements, and not fearing small changes—this is the spirit of Kaizen. It contrasts with the Western concept of "Innovation": while innovation seeks big leaps, Kaizen pursues the accumulation of small steps.

How It Works​

Kaizen is based on several psychological and organizational principles.

The Magic of Compound Effect: If you improve by 1% every day, after one year you'll be 37 times better (1.01^365 = 37.78). Conversely, if you decline by 1% daily, you'll be nearly at zero (0.99^365 = 0.03). Small changes aren't immediately visible, but over time they create exponential differences. This is the mathematical principle of Kaizen.

The Power of Habits: Big goals require willpower, but small changes can be automated into habits. "10 minutes of exercise per day" is easy to make into a habit, but "2 hours of exercise per day" is difficult to sustain. Kaizen pursues small changes at a sustainable level.

Minimizing Psychological Resistance: The human brain perceives big changes as threats and resists them (status quo bias). However, small changes don't feel threatening, so there's less resistance. "Let's change the entire company process at once" meets resistance, but "Let's improve one step of this task" is accepted.

Immediate Feedback Loop: Small changes allow for quick results verification. Feedback like "After changing it this way this week, efficiency increased by 10%" becomes motivation for the next improvement. Large projects take months to show results, but small Kaizen changes show effects in days.

Utilizing Collective Intelligence: Kaizen isn't just a CEO strategy—everyone on the ground participates. Those doing the actual work know the problems and solutions best. At Toyota, an employee makes an average of 10-15 Kaizen suggestions per year.

PDCA Cycle: Kaizen follows the repetitive cycle of Plan - Do - Check - Act. It's not about finding one perfect solution but continuously experimenting, learning, and improving.

Eliminating Muda: Continuously identify and eliminate "Muda," the Japanese word for waste. Toyota defined seven types of waste: overproduction, waiting time, unnecessary transportation, over-processing, inventory, motion, and defects. Reducing these one by one is Kaizen.

Implementation Methods​

Step 1: Observe Current State (Gemba)​

'Gemba (現場)' is Japanese for 'the actual place.' To improve, you must first go to the site and observe.

Questions to Ask:

  • How are we currently working?
  • What problems recur?
  • Where is time being wasted?
  • What feels frustrating or uncomfortable?

Observation Methods:

  • Follow the actual process from start to finish
  • Ask the workers directly (they are the experts)
  • Measure time
  • Find bottlenecks

Step 2: Find Small Improvement Opportunities​

Don't try to change everything at once. Choose one thing that's easiest and most impactful.

Prioritization Criteria:

  • Easy and high impact: First (quick win)
  • Difficult but high impact: Later (long-term project)
  • Easy but low impact: When there's time
  • Difficult and low impact: Don't do it

Examples:

  • "Redesign entire workflow" (X, too big)
  • "Place this button more prominently" (O, small and specific)

Step 3: Practice 1-Minute Improvements​

Start at a level so small that you can't fail.

1-Minute Kaizen Examples:

  • Desk organization: 1 minute before leaving work daily
  • Code refactoring: 1 minute review before commit
  • Meeting notes: 1 minute summary right after meeting ends
  • Exercise: 1 minute of stretching after waking up

Why 1 minute?

  • No psychological resistance (can't say "I can't spare 1 minute")
  • Sustainable daily
  • Seed for habit formation

Step 4: Run the PDCA Cycle​

Repeat small experiments.

Plan:

  • "This week, let's improve X using method Y"
  • Hypothesis: "If we do this, Z will improve"

Do:

  • Execute according to plan
  • Record time, effort, costs

Check:

  • What were the results?
  • Did it improve as expected?
  • Were there any side effects?
  • Measure with numbers (e.g., "Meeting time 30 min → 20 min")

Act:

  • If effective: Standardize and continue applying
  • If not effective: Analyze reasons and try another method
  • If unexpected problems found: Make this the next Kaizen topic

Step 5: Practice 5S​

5S is a fundamental Kaizen tool. It comes from the first letters of five Japanese words.

Seiri (Sort):

  • Distinguish between necessary and unnecessary items
  • Remove unnecessary items
  • Example: Organize files, tools, documents unused for 6 months

Seiton (Set in Order):

  • Arrange necessary items for easy access
  • "A place for everything, everything in its place"
  • Example: Keep frequently used tools within reach

Seiso (Shine):

  • Keep clean
  • Discover problems while cleaning
  • Example: Organize desk, computer, codebase

Seiketsu (Standardize):

  • Standardize the above three
  • Maintain the same level no matter who does it
  • Example: Create checklists, templates

Shitsuke (Sustain):

  • Make it a habit
  • Practice continuously
  • Example: 5 minutes of organizing time daily

Step 6: Share and Celebrate Small Wins​

Share improvements with the team and celebrate.

Sharing Methods:

  • "This week's Kaizen" time in team meetings
  • Simple sharing via Slack/email
  • Kaizen bulletin board

Importance of Celebration:

  • Recognition of even small successes provides motivation
  • Inspires others
  • Forms Kaizen culture

Step 7: Gradual Expansion​

Once successful in one area, expand to other areas.

Expansion Strategy:

  • Month 1: Personal work improvements
  • Month 2: Team process improvements
  • Month 3: Inter-department collaboration improvements
  • Month 6: Organization-wide system improvements

Examples​

Software Development Team's Kaizen​

Situation: Development team with many bugs and unstable deployments

Observation (Gemba):

  • Unexpected bugs occur with every deployment
  • Developers work late into the night before deployment
  • Testing is done manually
  • Code reviews are only superficial

Week 1 - Start Small Improvements:

  • Kaizen 1: "Create pull request checklist"
    • Checklist: Added tests? Updated docs? Security issues?
    • Time: Written in 30 minutes
    • Effect: PR quality noticeably improved

Week 2:

  • Kaizen 2: "Add one automated test per critical feature"
    • Before: Almost no test code
    • New: Add at least 1 test per new feature
    • First week: 5 tests added
    • Effect: Zero regression bugs in those features

Week 3:

  • Kaizen 3: "Improve code review rules"
    • Before: Just leave "LGTM (Looks Good To Me)" and approve
    • New: At least 1 specific feedback or question required
    • Effect: More active code quality discussions, increased team learning

Week 4:

  • Kaizen 4: "Pre-deployment checklist"
    • Before: "Just deploy and fix problems as they arise"
    • New: 5-minute deployment checklist (DB migration? Environment variables? Rollback plan?)
    • Effect: 50% reduction in deployment failures

Month 2:

  • Kaizen 5: "Automate CI/CD pipeline one step at a time"
    • Week 5: Automated test execution
    • Week 6: Automated lint and format checks
    • Week 7: Automated staging deployment
    • Week 8: One-click production deployment

After 6 Months:

  • Deployment failure rate: 30% → 3%
  • Test coverage: 10% → 70%
  • Deployment time: 3 hours → 10 minutes
  • Team satisfaction: Greatly increased ("I'm not afraid to deploy on Fridays anymore")
  • Important: Not one big project but accumulation of weekly small improvements

Freelancer's Daily Kaizen​

Situation: A freelancer always busy but not feeling growth

Day 1 - Observation:

  • Record how the day is spent in 1-hour increments
  • Discovery: Spending 1 hour daily answering the same inquiries repeatedly

Day 2 - Kaizen 1:

  • Write FAQ document (30 minutes investment)
  • Organize 10 frequently asked questions and answers
  • Effect: 50% reduction in inquiry response time

Day 3 - Observation:

  • Quote creation takes 30 minutes each time

Day 4 - Kaizen 2:

  • Create 3 quote templates (small, medium, large projects)
  • Effect: Quote creation time 30 min → 5 min

Week 2 - Observation:

  • Spending 20 minutes in the morning deciding what to do

Week 2 - Kaizen 3:

  • 5 minutes of planning time the evening before
  • Write "tomorrow's 3 most important things" on a post-it
  • Effect: Zero morning decision time, start work immediately

Week 3 - Observation:

  • Checking email easily takes over an hour

Week 3 - Kaizen 4:

  • Set email checking times (only at 10am, 2pm, 5pm)
  • Turn off notifications
  • Effect: Secured focus time, 30% reduction in email time

Month 2 - Observation:

  • Starting similar tasks from scratch every time

Month 2 - Kaizen 5:

  • Create "Reusable Assets" folder
  • Save reusable parts whenever completing a project
  • Templates, code snippets, design elements, etc.
  • Effect: 40% reduction in new project start time

Month 3 - Observation:

  • Energy depleted around 3pm

Month 3 - Kaizen 6:

  • Power nap at 3:15pm
  • Effect: Afternoon productivity recovered, no overtime needed

After 6 Months:

  • Work hours: 50 hours/week → 35 hours/week (decreased)
  • Income: 3 million won/month → 4.5 million won/month (increased)
  • Stress: Greatly reduced
  • Secret: Accumulation of daily small improvements

Personal Health Kaizen​

Situation: An office worker who breaks the New Year's resolution to exercise and get healthy every year

Week 1 - Starting Too Small:

  • Kaizen 1: "1 squat after waking up in the morning"
  • Ridiculously small but 100% achievable
  • 7 out of 7 days successful
  • Psychological victory: "I can do this"

Week 2 - Slight Increase:

  • Kaizen 2: "5 squats"
  • Still easy but slightly more meaningful
  • 6 out of 7 days successful (one day overslept)
  • No self-blame on failed day "Try again tomorrow"

Week 3 - Habit Expansion:

  • Kaizen 3: "5 squats + 10 seconds plank"
  • Total time 1 minute
  • 7 out of 7 days successful
  • Habit starting to take root

Week 4 - Time Addition:

  • Kaizen 4: "5-minute routine"
  • 10 squats, 5 push-ups, 30 seconds plank
  • 5 out of 7 days successful
  • Wanted to do more on weekends, did 10-minute workout

Month 2 - Natural Expansion:

  • Morning exercise now as natural as brushing teeth
  • Kaizen 5: "10-minute walk during lunch break"
  • Operating as habit, not willpower

Month 3 - Virtuous Cycle:

  • Feeling lighter makes wanting to exercise more
  • Kaizen 6: "Gym 2 times a week (30 minutes after work)"
  • Naturally, not forcefully

After 6 Months:

  • Morning routine: 10-minute home workout (daily)
  • Lunch walk: 15 minutes (almost daily)
  • Gym: 3 times/week, 40 minutes each
  • Stairs: Instead of elevator (10 floors or below)
  • Total change: -7kg weight, -5% body fat, improved energy level
  • Important: Not "1 hour of exercise daily from January 1st" but "1% improvement daily"

Why It Worked:

  • Too small to fail start
  • Sustainable through gradual increase
  • No perfectionism ("It's okay to miss a day")
  • Compound effect of habits

Benefits and Advantages​

Sustainable Change​

Major innovations often start enthusiastically but easily revert to original state within a month. However, small Kaizen is sustainable. "2 hours of exercise every day this year" is abandoned in January, but "1 minute of stretching daily" lasts a lifetime.

Reduced Psychological Burden​

"Let's completely innovate the company" is scary and creates resistance. "Let's just improve this one small thing" has no burden. Changes are easily accepted because the brain's amygdala doesn't perceive them as threats.

Fast Feedback and Learning​

Small experiments allow for quick results verification. You can immediately know "This change was good/not good," accelerating learning speed. Large projects take a year to know success or failure, but Kaizen can know in a week.

Compound Effect​

1% improvement daily equals 37 times after a year. This is the magic of Kaizen. Not visible right now, but over time it creates exponential differences. James Clear called this "Atomic Habits" in his book "The Power of Habits."

Minimized Failure Cost​

If big changes fail, losses are large (time, money, trust). However, even if small Kaizen fails, losses are minimal. You can move on with "This improvement didn't work? Let's try the next one."

Forming Organizational Culture​

Kaizen creates a culture of "self-improvement" rather than "following orders." When everyone on the ground becomes an agent of improvement, the entire organization evolves like a living organism.

Increased Creativity​

Small experiments stimulate creativity. Curiosity and playful spirit arise like "What if we try this?" "What about that?" Large projects become conservative due to fear of failure, but Kaizen allows free experimentation.

Sustained Motivation​

Frequent small successes trigger dopamine release and maintain motivation. Daily sense of achievement "I improved 1% today" creates long-term motivation. Big goals feel distant, but small goals can be achieved daily.

Precautions​

Beware of Impatience​

Don't abandon Kaizen and attempt big changes under pressure to "quickly show results." Kaizen seems slow but is the fastest path in the long term. Be patient.

Don't Dismiss as Too Small​

It's easy to dismiss thinking "How much difference will this make?" But ignoring 1% improvement means missing the compound effect. Believe in the value of small things.

Measurement and Recording​

Don't just "vaguely improve" but specifically measure and record. "Did meeting time decrease?" "Did bugs reduce?" You can only know if it's real improvement by checking with numbers.

Avoid Improvement for Improvement's Sake​

Improvement itself shouldn't be the goal. Always ask "Why are we improving this?" "Is this really an important problem?" Don't miss important things while improving trivial ones.

Importance of Standardization​

Without standardizing improvements, they revert to original state. "This way works better" must be documented, checklistified, or automated to persist.

Respect Individual Differences​

Improvements effective for one person may not be for another. Especially when doing Kaizen in teams, listen to everyone's opinions and decide together.

Let Go of Perfectionism​

Perfectionism of "must practice 100% daily" is the enemy of Kaizen. It's okay to miss a day. The important thing is starting again the next day. 70-80% practice is success enough.

Big Changes Also Needed​

Kaizen isn't a panacea. Sometimes fundamental redesign is necessary. Sometimes it's better to create anew rather than gradually improving an old system. Judge according to the situation.

FAQ​

Q: Which is better—Kaizen or Innovation? A: Both are needed. Kaizen is for daily improvements, innovation is for breakthroughs. Generally, investing 80-90% of time in Kaizen and 10-20% in innovation is a balanced approach. Toyota also pursues innovation (e.g., hybrid technology) alongside Kaizen.

Q: How small should I start? A: At a level "too small to fail." James Clear suggests the "2-minute rule." New habits should be doable within 2 minutes. Start not with "reading books" but "one page," not "exercising" but "putting on workout clothes."

Q: When can I see effects? A: Individual Kaizen shows effects within days, but compound effects become prominent after 3-6 months. At month 1 you feel "this much?" but at month 6 you're surprised "completely different!" Be patient and stay consistent.

Q: How should I introduce Kaizen in a team? A: Don't force it. First practice yourself and show small results. When you share "This change worked well," others become interested. Create 5 minutes of "this week's Kaizen" time in weekly meetings to share success stories. It must spread bottom-up, not top-down, to become true Kaizen culture.

Q: Do I need to make new improvements daily? A: No. Focus on making one improvement into a habit. Research shows it takes an average of 66 days to form a habit. After sustaining one thing for 2-3 months until it's automated, move to the next improvement. Don't try to change too many things at once.

Q: Is there a good way to record Kaizen? A: Simple is best. Write "today's 1% improvement" in one line in a notebook or record date and improvement in a spreadsheet. Complex apps or systems become burdens. The important thing is practice, not tools.

Q: What if Kaizen feels ineffective? A: Check two things. 1) Did you start small enough? If too big, it's unsustainable. 2) Did you do it long enough? Don't give up after 1-2 weeks, try for at least 2-3 months. If still no effect, try improving a different area. It might not be Kaizen itself but where you apply it that matters.

Q: I'm a perfectionist—can I be satisfied with small improvements? A: Perfectionists need Kaizen the most. Pursuing perfection often leads to starting nothing or burning out. Kaizen is practice in accepting "there is no perfection, everything can be improved." Paradoxically, accumulation of small improvements brings you closer to the excellence that perfectionism pursues.