TAKAOKA — In an isolated area of this 520,000-square-meter Toyota production site in central Japan's Takaoka — where 25 million vehicles have been produced since it opened in 1966 — Hisao Harada is using spray gun to paint the radiator grill of an iQ, a small city car. His movement is fast, fluid, precise.

Harada has been working here for 27 years and is a Toyota takumi, one of the company's 400 to 500 in-house experts who master to perfection a single technique and whose missions are very specific. One woman, for example, specializes in electronic circuit welding.

"We can send them anywhere in the world to train others, improve, fix problems," explains Toshitami Nagase, deputy head of Takaoka's painting workshop, where the Japanese company tests new techniques.

The takumis and their extreme specialization are essential to the success of Toyota, which became the world's largest car manufacturer three years ago. Between January and June 2014, the company sold 5.1 million vehicles globally. Sales rose 2% in the second quarter over the same period the previous year, to $62 billion.

The manufacturer had never sold so many cars in a single quarter, despite a 4% drop in Japan, the consequence of an April 1 hike in the value-added tax.

When the experts age out

Toyota plans to sell more than 10 million cars in 2014, which would be a first for any manufacturer. To reach this goal, the group relies on its takumis, though this source of expert wealth is being depleted.

"Most takumis are nearing retirement age," says senior technical executive Mitsuru Kawai. "We realized how important it was to pass on their knowledge."

First, the firm spots the best young workers in training. The selected ones then follow a three-year course, which includes one year in one of the company's Global Production Centers, before going to several factories to develop a form of companionship.

The project was developed after the severe recall crisis of the late 2000s that left Toyota badly shaken. In 2009 and 2010, the company had to recall close to nine million vehicles, most of them in the United States, for design flaws. This ended a reign of exceptional sales growth, which saw Toyota sell 500,000 extra cars every year.

The Japanese carmaker was the target of a strong media campaign. After taking the lead in June 2009, Akio Toyoda, the founder's grandson, had to testify before the U.S. Congress during a high-profile 2010 hearing. Toyoda later admitted that the company's development "may have been too quick."

"That was the worst crisis I saw in my 51 years at Toyota," Mitsuru Kawai remembers. Now 66, he grew up in Koromo, the central Japanese town that is the manufacturer's fiefdom and was renamed Toyota City in 1959. Kawai went through Toyota Academy as an apprentice. He climbed the ladder little by little and now leads the takumi project. "The previous crises, the oil or the financial crisis, were external problems," he says. "But with the recalls, it was about products that were our responsibility."

The whole affair forced Toyota to rethink and reorganize its quality control. At the urging of Akio Toyoda, the carmaker created an independent service in charge of these issues and delegated more power to regional subsidiaries to deal with incidents. Having spent 25 years in different positions and in different markets, this automobile fan knows the company's culture well. For him, the conception of a new model is similar to "the painstaking work of rebuilding a Shinto shrine." He decided they had to go back to the core values of the "Toyota way."

The promotion of new takumis is supposed to keep Toyota know-how alive, a principle that is not unlike monozukuri — literally "to make things" — itself deeply rooted in Japan's industrial culture. By doing so, the company is demonstrating its willingness to change the relationship between humans and the robots that are integral in car manufacturing.

"Don't believe that robots do better quality work than humans," explains Shinichi Kato, who is in charge of the painting workshop at the Takaoka factory. "Sure, a robot can repeat a task at a high-level. But somebody needs to teach it how to do it." And only someone who is an expert in his field can do that.

On the painting line, an endless flow of cars passes, and robots paint them. Sometimes, a human — a worker must be able to replace a machine that is stopped — takes over. That's when the similarity of the movements is striking. The robots at Takaoka are not jerky but instead are a perfect copy of the smooth workers' gestures. "Improvement after improvement, we've managed to optimize the robots' procedures and the quantity of paint we use," Kato says. Humans then control the work with a naked eye.

This all allows Toyota to reduce the number of employees in charge of one task, and as a result, to lower production costs. Thanks to robot improvement, the carmaker reduced the number of workers on a painting line from 16 to just six. "But we don't reduce the number of employees," says Mitsuru Kawai. "Those liberated are appointed elsewhere."

Improvements in the installation of car door seals allowed the company to save 39 cents in production costs per vehicle. Put together, these efforts have led to spectacular results. Since 2008, Toyota has reduced its costs by $14.4 billion.