The Role of Lean Team Leader 

Toyota Motor Corp. has been profitable nearly every year for more than half a century. For fiscal 2025, profit exceeded $31 billion. Even as the auto industry changed dramatically in the past decade and Toyota was criticized for not aggressively running out all-electric vehicles, profits continued to flow. Ironically, in early January of this year, Toyota North America posted an 8% increase in sales; “electrified” vehicles posted a 17.6 increase in sales and accounted for 47% of total sales. So much for not understanding the EV market and where it was headed.  

Just how does Toyota do it year after year? Is it the predilection to patiently assess market trends and then dynamically capitalize on them? Is it the Toyota Way, founded on continuous improvement and respect for people. Is it the famed Toyota Production System and the principles and tools to eliminate waste and enhance value to customer — clarity on True North (in terms of safety, quality, delivery, cost), continuous flow, pull systems, built-in quality, standardized work, heijunka, etc.? Is it the innovation and application of critical systems beyond manufacturing (product development, supply-chain management, sales and marketing, administration)? 

Of course, it’s all of these things. Yet throughout Toyota and other high-performing lean enterprises can be found a critical link necessary for these methods to achieve their full potential — the unique role of team leader.  

Where team leader roles are lacking, lean transformations are likely to struggle.

— Jamie Bonini, TSSC President

The team leader role at Toyota is fundamentally different from what is typically found in most organizations. Team leaders work between supervisors and frontline teams, supporting team members as they strive to perform their daily assignments and hit objectives associated with their work. “They’re not in a managerial role — they’re in a support or assist role,” said Jamie Bonini, President of the Toyota Production System Support Center (TSSC), a not-for-profit corporation affiliated with Toyota Motor North America that since 1992 has shared Toyota know-how with more than 500 small- to mid-sized companies in varied businesses, government entities, and non-profits. Jamie has worked with many team leaders in his 30-plus years at Toyota, and he said that where team leader roles are lacking, lean transformations are likely to struggle. 

Dr. Sarah Womack, an eight-year veteran of Toyota and author, said that when she began working on a line at Toyota she did not realize the extent to which leaders focused on reducing team member burden so they can perform work safely and with the highest level of quality and efficiency — it wasn’t just about increased output. She thought it was novel and clearly not something encountered in most U.S. plants.  

For team leaders to adequately support team members, they must have technical know-how of team members’ roles as well exhibit the necessary values required by Toyota, said Sarah. “Do you have what it takes, in other words, to develop good team member relationships? Can you build trust? Can you build trust quickly? Those are all extremely important on this journey that is hard to experience until you’re inside the company.” 

She said that when developing individuals to fulfil such roles, it has to happen “person by person” because not everyone brings the same capabilities to their roles. “It’s not a set of robots that you are producing, but rather a group of individuals with some common understanding of the importance of kaizen, the role of kaizen, and how important it is as it relates to fulfilling our customers’ needs. That collective group and common understanding is what ultimately can transform an organization.” 

Steven Spear — renowned management expert, author, and senior lecturer at MIT — recalled a recent visit to Toyota Georgetown, a facility that reduced the size of final assembly to 25% while retaining volume. This improvement occurred not from a great redesign, but incremental problem solving over the years. On the tour, Steven spoke with Keith, a frontline associate, who was being trained in problem solving and had 152 problems to be solved in his 30-foot station. He was currently at number 87 with the support of his team leader and group leader/supervisor.  

“Now think about this: 30 feet is about three minutes of cycle time, more or less,” said Steven. “So he found one problem per second in that area. And he was one guy… Multiply that by 10,000. Boom. That’s your answer for how you get your final assembly down to 25%.” 

One associate found one problem per second. Multiply that by 10,000. That’s your answer.

— Steven Spear, MIT Senior Lecturer

A Toyota team leader typically supports four to six team members, while a supervisor/group leader oversees four or five team leaders and is responsible for 20 to 25 team members. “If you don’t have the [team-leader-to-member] ratio and the skill and other factors, it’s impossible or very difficult for people to solve problems one by one as they occur immediately” — team member pulls the andon cord that signals an abnormality exists and he or she needs help, and then the team leader arrives, investigates, contains the problem, and solves to root cause, said Jamie of TSSC. “People can’t do it. There are just too many problems coming at them.” 

Toyota team leaders are far more than a manager who leads a team. Josh Howell, LEI President, recalled his experience leading a team at a Starbucks, floating between workstations, plugging holes in processes, and trying to keep everything running smoothly amid morning rushes. As he learned more about lean at the coffeehouse chain, he came to understand that the “heroics” he exhibited were simply covering up a poorly designed and poorly running operating system — “one where we weren’t actively monitoring for problems, we weren’t capably engaged in problem solving. We were simply doing our best, often going beyond human capacity to keep the store running, keep our customers happy, and keep the coffee flowing.”  

Josh’s role at Starbucks was the antithesis of a lean team leader. This becomes clear as Jamie defined the four main tasks required of Toyota team leaders: 

1. Maintain output: Team leaders ensure that work at frontline stations can be completed within the takt time so the assembly line doesn’t stop. If necessary, the team leader will backfill and assist team members to maintain takt (thus the need for technical knowledge of frontline work). 

2. Standardized work: The team leader coaches the team member on standardized work, confirms it through regular reviews and observation, writes the standardized work document that a team member follows, and continuously rewrites the document and gets agreement to make the work better (easier, faster, safer, fewer problems). 

3. Train team members: The team leader provides real-time, practical training right in the area, especially for new team members, supplementing fundamental skills taught offline. 

4. Solve problems: Beyond the immediate need to solve known problems at the surface as they occur and maintain a line’s output, team leaders solve problems in the work to prevent reoccurrence.  

The team leader’s proximity to problems on the line — both distance and time — helps with solving problems to root cause. “There’s a high likelihood that problem may have occurred very recently, right before that [andon] signal, so a lot of the evidence is fresh,” said Jamie. “That team leader is working right in that location to help attack that problem.” 

For organizations pursing lean without the team leader role — maybe they have some kind of management system, problem solving, and kaizen in place — the injection of team leaders will help align those pieces and dramatically move the needle. A first step is to figure out how many leaders are necessary. Jamie said the number (usually no more than six team members to one leader) depends on the: 

• Ease and speed with which the team leader can arrive and assist when a problem has been signaled 
• Complexity and frequency of problems signaled  
• Team member skill and experience 
• Team leader skill, experience, and familiarity with the team members’ process. 

The team leader becomes the critical connection in the “circuitry” of a lean management system. Steven remembered when he first saw and understood the Toyota circuitry in which a problem needed to be solved, someone had a need, then the problem was addressed, and the circuit closed. “That was the moment of realization that this is a system built around the ability to see problems and respond to them quickly. It’s a simple thing to say, but the hard work is to keep pushing and pushing and pushing so you can see problems in greater detail, with greater accuracy, at smaller scale, sooner before they have a chance to become big problems.” 

Steven Spear, Josh Howell, and Jamie Bonini and Michelle Thomas, TMMC Manager, will deliver keynotes at the Lean Summit in Houston on March 12-13. 

More about Toyota and team leaders: 

• “Steven Spear Talks about Competing with TPS and Problem Solving” podcast with Steven Spear, Josh Howell, and Mark Reich, LEI Chief Engineer Strategy 
• Are You Organized for Leadership?” article by Josh Howell 
• “A Toyota Take on Taking TPS to Others” podcast with Jamie Bonini, Josh Howell, and Mark Reich 
• Dr. Sarah Womack book Toyota’s Improvement Thinking from the Inside 

Steven Spear books and articles: 

• Wiring the Winning Organization 
• The High-Velocity Edge 
• “Decoding the DNA of the Toyota Production System” in the Harvard Business Review