I was re-reading The Birth of Lean, the Lean Enterprise Institute's collection of interviews with the people who built the Toyota Production System, and one answer from Eiji Toyoda is worth quoting in full. This is Eiji Toyoda on mistakes, and on what gets lost when we don't write them down. He led Toyota as president and then chairman, and oversaw the rise of that system from the management side. Here an interviewer asks what advice he would give the young managers who will run the company next. His answer:
“An awful lot of people these days are always thinking up excuses for whatever goes wrong. That's no way to make any progress. I always tell people to give their all to their work and not worry about mistakes. I also tell people to write up reports about what goes wrong, though not many actually do it. If we don't write down what went wrong, and we only store the experience in memory, we won't be sharing what we learned with the next generation, and that's no good. You occasionally see someone new on the job going around telling people how to do things and leading them into the same mistakes we went through 10 years ago.”
That interview dates to 1987. Read it again and tell me it doesn't describe a lot of workplaces in 2026.
“Don't Worry About Mistakes” Is the Part People Like
The line that gets quoted a lot is the easy one. Give their all to their work and not worry about mistakes. It sounds generous, and it is. Read by itself, though, it can also sound like permission to be careless, and I don't think that's what Toyoda meant at all.
Look at what comes right after. He tells people not to worry about mistakes, and in the very next breath, he tells them to write up what went wrong. Those two instructions belong together. They describe the same culture from two sides.
When people are afraid of being punished for mistakes, they hide them. They cover for the problem, or they minimize it and hope nobody noticed. Take the fear away, and you get something better than silence. You get the report.
I've written about this as the Fear Factor, or simply whether people feel safe enough to say, “I made a mistake” or “something's wrong here.” Eiji Toyoda was describing what we'd now call psychological safety decades before that phrase became common. He didn't need the terminology. He simply told people not to worry about mistakes.
Why Even Eiji Toyoda Couldn't Get People to Write Mistakes Down
Here's the line I'd underline twice.
“I also tell people to write up reports about what goes wrong, though not many actually do it.”
Read that again. The chairman of Toyota, the company everyone studies for its discipline, admits that even there, most people don't write up what went wrong. I like that bit of honesty. He isn't pretending it's easy. Even at Toyota, people don't always do it. But he still thinks it's worth asking people to try.
This reminds me of what I call the Futility Factor. Making it safe to report problems matters. But if nothing gets captured or improved, people eventually stop believing it's worth the effort.
And the cost of skipping the write-up isn't abstract. Toyoda names it. If the lesson lives only in someone's memory, it leaves when they do. Then a new person shows up, full of confidence, telling everyone how to do the job, and walks straight into the problem you already solved ten years ago. The knowledge was real. It just never got written down where the next person could find it.
Here's a Mistake I Logged in KaiNexus
I try to do what Eiji Toyoda described, and it's harder than it sounds. So let me show you one of mine.
A while back, I set up a LinkedIn event to stream one of my KaiNexus webinars. It was an experiment. Normally, people get access to the Zoom webinar by registering on our site.
About forty people registered through LinkedIn. When the time came, the tech setup didn't cooperate, meaning I hadn't set it up right, and the stream never went out on LinkedIn. Only those who had registered through Zoom could view it. I posted an apology and shared the recording on YouTube afterward. Not a disaster. Nobody got hurt. But forty people had registered, and the thing didn't work.
I logged it in KaiNexus, our own improvement-tracking software that we sell — and also use — the same way I'd log any other problem: what happened, why it happened, and what I'd change. The countermeasure was almost embarrassingly simple: run a test first. I wrote it down anyway. Otherwise I'd be trusting my memory instead of the process. I also noted, right there in the entry, that I wanted it to be normal for other people to post their own mistakes and lessons learned. It's hard to ask for that if I'm not willing to do it myself.
That's the same instinct behind my podcast, My Favorite Mistake, where I ask leaders to tell the story of a mistake and what they learned from it. It's why I wrote The Mistakes That Make Us. That's really the point. If the lesson stays with me, somebody else may have to learn it the hard way.
The Best Place to Store a Lesson Is the Process Itself
Logging a mistake like that is a good floor to stand on. Better yet, build the lesson into the work itself. Then the next person doesn't have to remember it because the process does.
Isao Yoshino, a retired Toyota leader I interviewed on My Favorite Mistake, tells a story from his first weeks at Toyota in 1966. He grabbed the wrong solvent and ruined a batch of paint. About a hundred cars had to be redone. He thought he would be fired. Instead, his leaders gathered the team and asked,
“How did this happen?”
They found that the two solvents sat side by side in nearly identical containers. So they separated them and labeled them clearly. The next new hire couldn't make the same mistake, because the workspace wouldn't let them.
That's Eiji Toyoda's point taken one step further. Don't leave the lesson in someone's head, or even in a report. Put it into the process, where it can't get lost.
Culture Decides Whether the Form Gets Filled Out
It's tempting to read “write up what went wrong” and reach for a template. A form. A field in the system. And you do need somewhere for the lesson to live, whether that's standardized work, an A3, a problem report, or a shared improvement platform other teams can search.
The tool isn't the hard part, though. The hard part is the culture that decides whether the form ever gets filled out honestly. People write up what went wrong when they trust the write-up will be used to fix the process, not to build a case against them. The moment a mistake report turns into evidence at a performance review, the reports dry up, and you're back to storing everything in people's heads and hoping.
This gets back to something I've believed for a long time. The right response to a mistake is to understand the system that allowed it. Punishment usually teaches a different lesson: keep your head down next time. As Deming reminded us, a bad system will beat a good person every time. And if people stop telling you about the system's problems, improving it gets much harder. Whether the next generation gets to skip this generation's mistakes comes down to how a manager reacts in the first ten seconds after someone says “I think I messed up.”
The Same Idea, Two Generations Apart
I open the chapter on preventing mistakes in The Mistakes That Make Us with a line from Akio Toyoda, the more recent chairman:
“It is in Toyota's DNA that mistakes made once will not be repeated.”
I love that line. But DNA makes it sound automatic, as if the company simply inherited the trait.
Eiji Toyoda, decades earlier, was describing how that actually happens. People give their all. They admit what went wrong. They write it down. Better yet, they improve the process so the next person doesn't have to learn the same lesson all over again. That doesn't happen automatically. It depends on the habits people practice and the environment leaders create.
So here's what I'd ask my own team, and what I'd ask yours. When something goes wrong this week, where does the lesson end up? In a report somebody can find a year from now, or in one person's memory, waiting to walk out the door?
