The three faces of lean
The Machine That Changed the World ushered in a new era by asserting that “lean production” was the future — and that companies needed to commit to it or be wiped out by competitors that did. Later, we learned that behind lean production systems there was a way of thinking — lean thinking — that needed to be adopted by all executives and managers. And the lean production model did not belong to Japanese automakers in general, but to Toyota, originating in the Toyota Production System (TPS).
Since then, Toyota has continued practicing and refining TPS, and, outside Toyota, there has been an explosion of lean books, training, certifications and lean programs in virtually every sector — private companies, governments, nonprofits and NGOs. Having held a privileged position as a participant in and observer of lean transformations, I have noticed three general approaches, which are often adopted in isolation. I argue that these three faces of lean, when combined, are far more powerful than any one of them individually.
- Lean as technical solutions — The simplest way to understand lean is as a technical system whose goal is to make a specific value flow to each customer by eliminating waste.
The vision is like that of a river, with no dams or rocks to interrupt the flow and cause stagnation. Value stream mapping (VSM) became the preferred tool for visualizing the current flow with all its undesirable waste. The more experienced users then define a lean future-state map. The next step is to create an action plan with what, when and who. Then all the future-state lean countermeasures are implemented and, voilà: you will have a lean system that delivers value to the customer more smoothly, with high quality, low cost and fast response times.
(It is important to note that VSM, called the material and information flow diagram at Toyota, was created for the purpose of showing only the technical flows of material and information — and at a fairly macro level, at 10,000 feet. There is absolutely no human system represented. And, in Toyota's view, the future-state map is an overall vision of what one wants to achieve — not a set of tools to be implemented.)
In other cases, organizations implement lean tools as isolated solutions. "We don't have standardized work, which is part of a lean system, so let's write up standardized work and post a sheet for each process, then audit the operators to make sure they follow the steps."
"Toyota doesn't schedule production, it pulls using kanban, so let's replace our scheduling with pull systems." And so on.
The goal becomes transforming processes as quickly as possible, with actions driven mainly by lean specialists and the change management function. This process is often called a “lean conversion”, with the expectation that, in a few weeks or a few months, the company will go from “not lean” to “lean”. This path is common among those who use kaizen events as the main transformation approach or who drive lean through lean six sigma black belts.
If you ask someone at Toyota who is well versed in TPS what worries them most about the lean movement, the answer will be almost unanimous: many people think it is just about tools. At Toyota, they take seriously the fact that TPS is a system — and that it includes both the technical and the social aspects, working together toward clear objectives: the purpose. Somehow, this seems to have been lost in the obsession with implementing tools as quickly as possible.
TPS is a system that includes both the technical and the social aspects, working together toward clear objectives — the purpose.
This is not to say that transforming a value stream based on value stream mapping or introducing lean tools such as standardized work is a waste of time. Creating connected processes is a powerful intervention and can generate countless benefits. There is an art to developing lean solutions, and I have marveled at the creativity of the true TPS masters — although most of us mere mortals do not have the same level of expertise.
Deploying lean tools is relatively quick and efficient, and, as human beings, we like to see quick results for our efforts. However, many of us have experienced the deterioration of these systems after the experts leave, when they move on to other projects.
- Lean as social solutions — Another popular way to understand lean is as something entirely centered on people.
There are many books — including mine — that describe Toyota's people management systems, especially on the shop floor. The most visible are the daily management meetings, in which team members gather in a circle (huddle) to discuss what happened the previous day, what to expect from the current day and how to improve processes. They gather around well-designed visual boards, with key performance indicators (KPIs) and green, yellow and red status signals. The focus should be on the red.
You can do this. But there is another essential ingredient: the people who lead these meetings. Toyota calls them “team leaders” (team leaders) — production operators who have been trained in leadership skills and the fundamentals of TPS — and “group leaders” (group leaders), who are the first line of supervision. This is a bit more challenging than just installing boards and scheduling meetings. You need to involve Human Resources and, if there is one, the union, in formally creating these positions. Since you already have supervisors, you can train them in lean and problem solving, thus creating a green belt program. Later on, the team leader role can be added.
Once you see the benefits of daily management meetings, you then study strategy deployment (policy deployment) and implement tiered meetings (tiered meetings) throughout the organization, so that there are aligned goals and progress tracking against those goals. Those TPS experts can sleep soundly at night, knowing that you have gone beyond the tools.
What you have done is intervene in the social system, but, in a way, this is similar to the technical-solutions approach. You copied social structures and activities and assumed you could implement these solutions in a standardized way, as if following a ready-made recipe. There is usually little training involved, and the assumption is that the mass deployment of meetings, visual boards, obeyas and cascading goals will, by itself, have some power — without actually developing deep capability in the leaders.
Without developing leadership, we may have the positions defined on the organizational chart and people filling them — but, in practice, we do not actually have the leadership roles being performed.
Even more than with technical solutions, the quality of these interventions tends to be low in most groups and, quickly, the level of interest dissipates, turning everything into empty rituals. There is, in fact, an important set of skills in Toyota's leaders — including in the team leader role — and Toyota is obsessed with training and development.
Without developing leadership, we may have the positions defined on the organizational chart and people filling them — but, in practice, we do not actually have the leadership roles being performed.
- Lean mindset — A third way to understand lean is as a way of thinking.
I have had the pleasure of interviewing several direct students of Taiichi Ohno, considered by many to be the father of the Toyota Production System (TPS). Being given the task of learning from the master was an intimidating experience. What would he teach first? About cells, kanban, andon? Ohno did none of that. He would draw a circle on the floor and order the apprentice to stand there, observing. He would come back from time to time and ask what the person saw. When the apprentice struggled to describe what was going on, Ohno would seem irritated and tell him to keep observing. I asked one of his students how this training ended, and he replied that, at the end of the day, Ohno would say: “You look tired. Go home.” The best students did not need to come back the next day.
What Ohno and his disciples did was put the apprentice in a position to learn through practice. They were teaching a way of thinking — what was described in the first TPS manual as “scientific thinking”. Step one: learn to observe deeply in the gemba. When you think you have understood everything, observe a little more. There is always a new layer of reality to be perceived. This is only the first step — one of many skills required to be an effective leader at Toyota. As with any complex skill, we learn by breaking it into smaller parts and practicing each sub-skill repeatedly, with corrective feedback, until we master it — and then we move on to the next micro-skill. In Japanese martial arts, each of these skills is called a kata. And you start by performing it exactly as the master instructs.
Hajime Ohba was one of Ohno's best students. He was sent to the United States to teach TPS, and he did so by creating what is today called the Toyota Production System Support Center (TSSC). He refused to teach in a classroom. Instead, he would meet with the executive team to define the vision and a big challenge, and together they would choose a “model line” — an area within an industrial plant to be used as a learning laboratory.
Ohba also taught the Toyota members assigned to TSSC, who helped on the consulting projects. He trained them in the material and information flow diagram technique, but did not allow them to show the diagrams to clients. He wanted the clients to learn by doing — starting with the challenge, identifying the next problem and learning through rapid, repeated PDCA cycles until they built a system that met their own objectives. He was teaching a way of thinking, not a method for drawing diagrams.
Mike Rother incorporated the concept of kata and created what he calls the “improvement kata” (improvement kata) and the “coaching kata” (people development kata). He developed a four-step model for continuous improvement:
- Define the long-term challenge,
- Understand the current condition,
- Define the next short-term target condition,
- Experiment until you reach that condition.
Then reflect and repeat — continuously — on the way toward the bigger challenge. He calls this a practical model of everyday scientific thinking.
The central idea of kata is to practice it, not to implement it as a ready-made solution, with the goal of developing skills and mindset. However, it is common to see people trying to adopt the katas as if they were just another problem-solving method, something to be implemented as a “lean solution” and added to the tool kit for a mass deployment. This runs completely counter to the purpose of kata, which is to learn a way of thinking through deliberate, long-term practice.
Not surprisingly, this four-step process looks very much like what Toyota's trainers do. They train leaders in the gemba, on real projects, always starting with a big, seemingly overwhelming challenge. They suggest that the student observe the process and then choose something smaller to work on first. They encourage the student to test ideas quickly and cheaply — and thus learn fast, even if that means failing fast. They are relentless and push the student to a level of focus and persistence he did not even know he was capable of reaching.
Rother observed these Toyota masters in action and created Toyota Kata to simulate their teaching process. If you visit a Toyota plant and look beneath the surface, you will find an obsession with developing scientific thinking — or, as Toyota calls it, problem solving — at every level. Every manager is, at the same time, a student and a mentor, and training happens every day, in the gemba.
Putting it all together
By now, it should be clear that the three faces of lean are not mutually exclusive. There is indeed a body of knowledge made up of powerful tools and relevant social structures. But copying them exactly as they are misses the point. They are ideas, concepts, principles — starting points for reflection. They can help you develop a future-state vision.
But, at the end of the day, you are trying to lead positive change within your specific context, with its own challenges and obstacles, to reach the goals you have set — ideally in a strategic way. Even if you had a future-state vision identical to Toyota's, your starting point would be different, and so would the obstacles. And, in practice, you are likely to be in a different business, with distinct business challenges and your own technical systems.
I gave the last chapter of the second edition of The Toyota Way the title: “Be mindful and evolve your enterprise.” I say this in all seriousness. TPS evolved continuously, over decades — not as a change management program planned in a meeting room. It keeps evolving to this day.
What sustains TPS is a way of thinking: scientific thinking. This way of thinking is trained exhaustively — and persistently — in every leader. Scientific thinking can go with you into any context and situation. It allows you to apply perhaps the most sacred principle of lean — and probably the key to organic growth: PDCA.
An obvious question, given the existence of multiple approaches to lean, is: What is the best way to apply these three faces of lean? If you ask a well-trained Toyota leader how to apply lean, with what timing and in what sequence, the answer will probably be: “It depends.”
If you ask Mike Rother, he would say not to approach the process as deploying solutions through a rigid method, standardized like a cake recipe, but rather as a scientifically oriented learning process.
Follow the steps of the kata model and its practice routines:
What is your vision? — not that of the lean gurus or of Toyota.
What is your current state?
What are your strategic plans?
How do you turn this into clear challenges?
And then, start developing leaders who think more scientifically, as they learn while moving toward the challenges. What are you learning?
This is an evolutionary process. It is the path to creating a learning organization. And, in a sense, it is the opposite of the mass deployment of standardized solutions.
Of course, there are very powerful principles, tools and social structures that Toyota has discovered along its journey. Studying them, considering them in building your vision, integrating them into your target conditions and even developing your own value stream vision for each customer is extremely worthwhile.
At certain moments, you may want to teach lean concepts. But I prefer “just-in-time” teaching: teach the tool when the student needs it.
I am not suggesting this is easy. Nor am I saying it is likely to happen in most organizations. In that sense, Toyota really is special. There is room for a “kamikaze” deployment, aimed at quick efficiency gains or at solving quality problems that threaten to bring the company to a halt. There are also positive lessons that can emerge from huddles, cascading goals and value stream mapping. None of this will be in vain. But, at some point, it is desirable to take the next step — lean thinking practiced scientifically.
