Editor's note: Katie Anderson's last column covered "no problem is a problem," the importance of surfacing and identifying problems rather than letting them bubble under unaddressed. Once the problem has been named and acknowledged, leadership's response shapes what happens next.

One of the key practices Toyota developed to support a culture of problem-solving is one you may have heard of: andon.

Andon is a Japanese word that means signal. On the Toyota production line, and at many other Japanese companies, a frontline worker who runs into a problem they can't solve in the time allotted for their task can signal that they need help, by pulling a cord or pushing a button that sets off a light or a sound.

But the signal is only half of it. It's not enough to say, "we empower our people to make problems visible."

What makes andon actually work is what happens next: the leader's response. At Toyota, a team leader comes over to help solve the problem, and only if they can't fix it together in the allotted time does the line actually stop. If signaling a problem gets you punished, or gets you nothing at all, you learn very quickly to stop making the bad news visible.

Creating the conditions where people feel able to signal—and where leaders both know how to respond and actually do—is the real work of building a culture of continuous improvement. Signal when there's a problem; respond to help. It's a virtuous cycle that reinforces improvement, starting with bad news first.

How Andon Transformed NUMMI

Toyota Leader Isao Yoshino believes andon is one of the fundamental management practices behind one of the most famous manufacturing turnarounds in history—the NUMMI joint venture between Toyota and General Motors in the mid-1980s. GM's Fremont, California, plant had been its worst-performing, with such a toxic culture that workers had been known to sabotage the cars coming down the line.

Yoshino, with a team that included John Shook, was responsible for the Toyota training program that brought cohorts of American frontline leaders to Japan for three weeks: a week of classroom instruction and two weeks working the assembly line alongside a Japanese counterpart.

When Toyota leaders first explained andon in the classroom, the former GM team leaders didn't believe it was possible. No, no, you cannot do that, they'd exclaim. At GM, highlighting a problem or stopping the line got you fired; the unspoken norm was to pass the problem down and let someone fix it at the end.

Then they saw it for themselves. Out on the floor over the next two weeks, they watched their Japanese counterparts pull the cord to signal a problem. Instead of blame, or no response at all, a team leader came over to help. Immediately. And it happened multiple times a shift.

The NUMMI leaders were shocked, and kept asking: is it really okay that I can stop the line? Within a week, they were pulling the cord themselves. As Yoshino puts it, the training staff never told them what to do. They provided the opportunity, and the workers decided for themselves which way was better.

Within a year, with largely the same workforce, NUMMI became one of the best-performing plants in GM's system. Same people. What changed was the leadership culture—and andon was at the center of it.

Andon Doesn't Stop at the Shop Floor

Andon isn't only for frontline employees signaling a problem on the line. The same principle— signal when there's a problem, and respond to help when someone does—applies all the way up to the most senior levels of an organization. It's about how leaders at every level surface bad news to those above them, whether a director to their vice president or a CEO to their board.

Yoshino experienced this too, at the very end of his career, the bookend to that first paint-shop moment, more than 40 years on.

In his final years at Toyota, Yoshino was leading a new and struggling business: a line of water ski boats that ultimately failed, at a cost of more than $13 million. In the last year of the venture, knowing the business likely couldn't be saved, Yoshino, a senior director, did something that took courage. He reached out to Fujio Cho, the president of Toyota, to share his concerns, and asked him to fly out to the plant in Orlando and see it for himself.

Mr. Cho came. When he arrived, Yoshino did what most of us would do in front of the most senior leader in the company: he started with the good news. Mr. Cho stopped him and asked, “Why are you telling me what's going well? he asked. I came because I want to hear what is not working.”

Cho, along with Yoshino, already knew the business likely couldn't be saved. But as Yoshino reflects, Cho came anyway; not to rescue it, but to show every leader at Toyota what a leader is supposed to do when there is bad news, even at the very top. You go see, you show support, and you find out how you can help.

Two moments at opposite ends of one career, four decades apart, at completely different scales, and the same leadership response each time. It isn't the mistake, the failure, or the surfacing of bad news itself that builds a culture of learning. It's how the leader responds. Not to blame, but to support.

Respond Down, and Signal Up

Creating this kind of culture asks two things of us as leaders and team members, and both have to be true at once.

The first is to respond down. When someone signals a problem to you—a mistake, a safety issue, a piece of bad news—your job is to come toward it and help, not to assign blame. Sometimes it's as simple as saying thank you for telling me. That response is what makes it safe for the next person to speak up.

The second, and harder one, is to signal up. Most of us were rewarded in school for having the answer, and promoted early in our careers for being the one who could solve the problem ourselves. We raise our hands when we have the answer. It takes real courage to raise your hand to say you have a problem, that something is off course, or that you need help. A culture of bad news first only holds if leaders are willing to signal up themselves, not just ask it of their teams.

That is andon at every level. It's not about the physical cord or button, but the response on the other end of it—and the courage to reach for it.

Today, the signal keeps getting easier—a button, an app, a pattern surfaced by AI faster than any person could catch it. But technology is an amplifier, not a substitute: As I've written about in Jidoka and the future of work, technology can make a problem visible, but the judgment to respond—and the culture that makes it safe to signal at all—is still the work of a leader.

Reflect: Holding on vs. Signaling up

Where are you holding onto bad news or a problem, hoping it resolves on its own before anyone has to know? What would it take to signal up sooner—so that help, and learning, can come sooner too?