Personal Development · The guide

Kaizen: Continuous Improvement for Your Career and Learning

Kaizen explained: its roots at Toyota, Deming's PDSA cycle, the honest math behind getting 1% better, and a weekly loop to improve your skills and career.

Mauricio Esparza By ·Published ·10 min read
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Short answer

Kaizen is the Japanese practice of continuous improvement: small, frequent changes made by everyone, every day. It grew out of Japanese manufacturing, especially Toyota, and is often run through Deming's Plan-Do-Study-Act cycle. Applied to a career, it means a weekly loop: pick one skill, test a small change, measure the result, keep what works.

That matters more in the AI economy, not less. Tools change every few months. The people who stay valuable aren't the ones who learned one tool once. They're the ones with a system for getting better.

In short

  • Kaizen roughly means "change for the better". In companies it means improvement that is continuous, incremental and shared by everyone.
  • Toyota built daily improvement by all employees into its production system. Masaaki Imai's 1986 book brought the word to Western managers.
  • PDSA/PDCA is the engine. Deming preferred "Study" over "Check": predict, compare, update your theory.
  • "1% better every day" is correct math (1.01^365 ≈ 37.8) but a misleading forecast. Real skills don't improve at a steady daily rate.
  • For careers, Kaizen plus deliberate practice gives you a weekly loop that builds proof of capability, not just motivation.

What kaizen means

The word joins kai (change) and zen (good, or for the better). The Kaizen Institute, founded by Masaaki Imai in 1985, translates it as "change for the better". In ordinary Japanese it's a normal word for improvement. As a management idea it means something more specific:

  1. Continuous. Improvement isn't a project with an end date. It's how work is done.
  2. Incremental. Many small changes rather than one big bet.
  3. Everyone. The person doing the work is the best placed to improve it, not only managers or consultants.
  4. Standard-based. You improve from a documented way of working, then update the standard when a change proves better.

That last point is the one people skip. Without a standard, you can't tell whether a change helped. You just have a different mess.

Where kaizen came from: Japanese management and Toyota

The Toyota Production System

Toyota describes its production system as aimed at the complete elimination of waste in pursuit of the most efficient methods. It rests on two pillars:

  • Jidoka: machines and people stop the line when something abnormal happens, so defects don't travel downstream. Toyota traces this back to founder Sakichi Toyoda's automatic loom.
  • Just-in-Time: making only what is needed, when it is needed, in the amount needed. Toyota credits Kiichiro Toyoda with the idea, and Taiichi Ohno, with Eiji Toyoda's support, with establishing the system.

Kaizen is the daily habit that keeps both pillars improving. In Toyota's own description, all employees make incremental improvements to eliminate muda (waste), mura (unevenness) and muri (overburden).

Masaaki Imai brings the word to the West

In 1986 Masaaki Imai published Kaizen: The Key to Japan's Competitive Success. According to the Kaizen Institute, which he had founded the year before, the book took the word into the global management vocabulary. Imai's contribution wasn't inventing improvement. It was naming and explaining a way of working that Japanese companies were already practicing, in terms Western managers could apply.

Deming, Shewhart and the PDCA cycle

Deming in Japan

W. Edwards Deming was an American statistician. The Union of Japanese Scientists and Engineers (JUSE) invited him to Japan in July 1950, where he taught an eight-day course on quality control in Tokyo and a one-day course for top management in Hakone. JUSE then created the Deming Prize to commemorate his contribution and to keep quality control developing in Japan. It's still awarded today.

PDSA vs PDCA

The improvement loop most people call PDCA (Plan-Do-Check-Act) has roots in the work of Walter Shewhart at Bell Laboratories, who mentored Deming. The Deming Institute is clear that Deming himself emphasized PDSA: Plan-Do-Study-Act.

  • Plan: decide what you want to improve, what change you'll try, and what you predict will happen.
  • Do: run the change, ideally small.
  • Study: compare the actual results with your prediction. What did you learn?
  • Act: adopt the change, adapt it, or abandon it, then plan the next cycle.

The difference between "Check" and "Study" isn't cosmetic. Checking asks "did it work?". Studying asks "was my theory right, and what does the gap teach me?". Deming's view, as the Institute explains it, is that new knowledge is always guided by a theory. If you never write down a prediction, you can't learn from being wrong.

This is the same logic as the scientific method MitHub uses to operate any system: observe, form a hypothesis, build, measure, learn, adjust.

The "1% better every day" idea, with honest math

James Clear popularized the compounding version of continuous improvement. On his site he tells the story of British Cycling under Dave Brailsford, which looked for many small improvements across every part of performance. He then makes the point that 1% better each day for a year leaves you about thirty-seven times better, while 1% worse each day takes you close to zero. His book Atomic Habits builds on this idea that small changes, repeated, add up.

Let's check the math, and then be honest about what it does and doesn't mean.

The arithmetic is right

Improvement ratePeriodsResult
1% better per day365 days1.01^365 ≈ 37.8x
1% worse per day365 days0.99^365 ≈ 0.03x
1% better per day, only workdays250 days1.01^250 ≈ 12.0x
0.1% better per day365 days1.001^365 ≈ 1.44x
1% better per week52 weeks1.01^52 ≈ 1.68x
2% better per week52 weeks1.02^52 ≈ 2.80x
Add 1% of your starting level daily (no compounding)365 days1 + 3.65 = 4.65x

Clear's own article includes a note that the linear version gives far less than the exponential one, which is exactly the point of the comparison: compounding happens only when each gain becomes the base for the next.

Why the promise is misleading anyway

  1. You can't measure 1% of a skill. What is 1% better at writing, negotiating or designing a workflow? The number is a metaphor.
  2. Skills don't improve at a constant rate. Early gains are fast, then they slow down. Plateaus are normal.
  3. Not every gain compounds. A faster keyboard shortcut saves time. It doesn't make the next improvement bigger.
  4. Some days go backwards. Illness, bad weeks, a changed job. Real curves are jagged.

What is actually true

Compounding in a career is real, but it comes from a specific mechanism: improvements that stick and become the base for the next ones. Learning to structure data makes learning automation easier. Automating one process frees time to design a better one. Shipping one visible project makes the next opportunity easier to get.

A more honest target: one kept improvement per week. If each one is worth "about 1%" of your effectiveness, that's around 1.68x in a year. Not 37x. But real, and it starts the next year from a higher base.

Deliberate practice: the Kaizen of skills

Kaizen tells you to improve continuously. Deliberate practice tells you how to improve a skill.

The term comes from psychologist K. Anders Ericsson and colleagues, whose 1993 paper in Psychological Review studied violin students and argued that accumulated deliberate practice (effortful activity designed specifically to improve performance, usually with feedback) explained much of the difference between skill levels.

That strong claim has been tested since. A 2019 replication by Brooke Macnamara and Megha Maitra, published in Royal Society Open Science, found that practice still mattered, explaining about 26% of the variance in performance, but much less than the roughly 48% reported in the original study. The authors noted that 26% is not trivial, but it doesn't support the idea that practice alone largely explains expert performance.

The honest takeaway for your career:

  • Practice matters a lot. It's the part you control.
  • It isn't everything. Starting point, opportunity, teaching quality and environment matter too.
  • The type of practice matters. Repetition without feedback builds comfort, not capability.

Deliberate practice has four practical ingredients you can use today:

  1. A specific target just beyond your current level.
  2. Focused effort, not background repetition.
  3. Fast feedback from a result, a reviewer or a metric.
  4. Adjustment based on that feedback.

Read that list again and you'll see PDSA wearing a different outfit.

The MitHub Kaizen Loop for your career

MitHub's thesis is simple: become more valuable in the AI economy. Continuous improvement is how that happens week after week. Here's the loop, built on PDSA and deliberate practice.

Weekly loop (60 minutes total)

1. Pick one capability (Plan, 10 min). Not "get better at AI". Something observable: "write a clear brief for an AI agent", "build a lead-enrichment table", "explain a pipeline report in five minutes". If you don't know which one, start with how to find what you're good at or the skills that make you more valuable.

2. Write a prediction (Plan, 5 min). "If I use a checklist before sending an automation to review, I'll get fewer than two correction comments."

3. Run one small change (Do, during the week). Keep it small enough to finish and easy to undo.

4. Measure against the prediction (Study, 20 min). Count what you can count: time, errors, comments, replies, completion. Write one sentence on why the result differed.

5. Keep, adapt or drop (Act, 10 min). If it worked, make it your new standard: a template, a checklist, a saved prompt. Standards are how gains stick.

6. Leave a trace (15 min). A short note, a screenshot, a before/after. Over months, these traces become proof of work. MitHub treats that proof as more convincing than credentials, which is why the journey goes Learn → Build → Create value → Prove → Earn → Improve.

Template

WeekCapabilityPredictionChange triedResultKeep / adapt / dropNew standard
1
2
3

Using the capability ladder

MitHub describes four levels of capability: Doer (executes tasks by hand), Director (directs AI and systems to do the tasks and judges the output), Designer (designs the systems and workflows) and Owner (owns the outcome and the business result). Kaizen helps you climb it on purpose:

  • As a Doer, improve speed and quality on one task, then write it down.
  • Once it's written down, it can be delegated to AI. Now you're a Director, improving how you brief and review. (More in director vs doer.)
  • When you improve the whole flow rather than one step, you're acting as a Designer. That's systems thinking applied to your own work.
  • When your loop measures business results rather than personal effort, you're behaving like an Owner.

A worked example (hypothetical)

Imagine Daniel, learning GTM engineering while working full-time.

  • Weeks 1–2: Capability: building a clean lead list. Prediction: using a written column checklist will cut his cleanup time in half. Result: it cuts it by about a third, and he finds he keeps forgetting phone formatting. He adds that to the checklist. New standard: a saved checklist.
  • Weeks 3–4: Capability: explaining his work. Prediction: a three-sentence summary (problem, what I built, result) will get a reply from his mentor within a day. It does once, not twice. He adds a screenshot. Standard: summary plus one image.
  • Weeks 5–8: Capability: automating one step. He connects the list to a simple workflow so enrichment runs without him. His role in that step shifts from doing to directing.

Nothing here is dramatic. After two months, Daniel has four standards, a small automation and a written trail of what he learned. That trail is the start of a portfolio, which is exactly what the case study chapter of MitHub's faculty asks for.

Common Kaizen mistakes

  1. Changing too many things at once. You won't know what worked.
  2. No prediction. Without it, every result feels like success.
  3. No standard. Gains that aren't written down disappear by next month.
  4. Chasing the 37x curve. Expect jagged progress and plateaus.
  5. Improving the wrong thing. Getting 10% faster at a task AI will do for you is a weak investment. Use a prioritization tool like the Eisenhower Matrix to pick what's worth improving.
  6. Keeping it private. Improvement nobody can see doesn't raise your market value. Leave traces.

How Kaizen fits the rest of your direction

Kaizen answers "how do I get better?". It doesn't answer "better at what?". For direction, see ikigai for career direction. And if you want a structured place to practice on real revenue problems, the Faculty of Revenue Reverse Engineering is built around that same loop: diagnose, prove value fast, operate, improve.

Key takeaways

  • Kaizen means continuous, incremental improvement by everyone, built on a standard you keep updating.
  • It became central to the Toyota Production System and reached Western managers through Masaaki Imai's 1986 book.
  • Deming taught quality in Japan in 1950 and preferred PDSA, because studying a prediction is how you learn.
  • 1.01^365 ≈ 37.8 is correct math and a poor forecast. One kept improvement per week is a realistic, compounding target.
  • Deliberate practice matters, though less than early research suggested. Focus, feedback and adjustment are what make practice count.
  • Run a weekly loop, write standards, and leave traces. That's how improvement becomes proof, and proof becomes value.

Frequently asked questions

What does kaizen mean?

Kaizen combines the Japanese words for change (kai) and good (zen), usually translated as change for the better. In business it means continuous, incremental improvement involving everyone.

Did Toyota invent kaizen?

Kaizen is a common Japanese word, but Toyota made daily improvement by all employees a core part of the Toyota Production System. Masaaki Imai's 1986 book introduced the term to Western managers.

What is the difference between PDCA and PDSA?

Both are improvement cycles. Deming preferred PDSA (Plan-Do-Study-Act) because studying means predicting a result, comparing it with what happened and updating your theory, not just checking pass or fail.

Is 1% better every day really 37 times better in a year?

1.01 to the power of 365 is about 37.8, so the math is correct. Real skills don't improve at a steady daily rate, so treat it as an illustration of compounding, not a forecast.

Sources

  1. Toyota Production System — Toyota Motor Corporation (accessed 2026-09-17)
  2. Masaaki Imai — Kaizen Institute (accessed 2026-09-17)
  3. PDSA Cycle — The W. Edwards Deming Institute (accessed 2026-09-17)
  4. How was the Deming Prize Established — Union of Japanese Scientists and Engineers (JUSE) (accessed 2026-09-17)
  5. Marginal Gains: This Coach Improved Every Tiny Thing by 1 Percent — James Clear (accessed 2026-09-17)
  6. The role of deliberate practice in expert performance: revisiting Ericsson, Krampe & Tesch-Römer (1993) — Royal Society Open Science (via PubMed Central) (accessed 2026-09-17)
KaizenContinuous ImprovementPDCADeliberate PracticePersonal Development
Mauricio Esparza
Mauricio EsparzaGTM Systems Lead · Revenue Engineer · Founder of MitHub. Designs and runs revenue systems for multi-location businesses: AI voice campaigns, enrichment, CRM automation and attribution. Founded MitHub to teach the method in the open.

Part of Personal Development on MitHub.

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