By: Sergio Niyama

 

Many people ask me what the “secret” of Toyota is. When we talk about Lean, we are talking about the Western interpretation of TPS (Toyota Production System).

However, the number one mistake starts right here: treating Lean as a “toolkit” rather than a management philosophy.

1. What is the Lean concept from my perspective?

For me, Lean is the relentless pursuit of waste elimination (Muda) through people development. In TPS, the central pillar is not machines, but the human factor.

The concept is based on two fundamental pillars:

Just-in-Time: producing only what is needed, at the right time, and in the right quantity.
Jidoka (Autonomation): giving intelligence to the machine and autonomy to the operator to stop the line whenever something is wrong.

The most common mistake is focusing only on the technical flow while forgetting that, without a Kaizen (continuous improvement) culture deeply rooted in employees’ DNA, the system collapses as soon as the consultants leave.

2. What is it for, and what are the real benefits?

Contrary to what many believe, Lean does not exist merely to “cut costs.” Its purpose is to generate customer value with maximum quality, speed, and stability.

When implemented correctly, the benefits are clear:

• Drastic Lead Time reduction: products reach the market faster.
• Quality at the source: less rework and less scrap.
• Team engagement: people who think, not merely execute.
• Flexibility: the ability to respond to market changes without relying on large inventories.

The mistake here is financial short-sightedness: focusing only on immediate cash gains while ignoring long-term process sustainability.

3. Context and Industry: Where does it apply?

Although Lean was born on Toyota’s factory floor, it is universal. I have seen it generate results in different contexts:

• Industry: on the shop floor, observing machines and operators.
• Healthcare (Lean Healthcare): reducing queues and hospital errors.
• Services and Offices (Lean Office): eliminating bureaucracy and excessive approvals.
• Agribusiness and Logistics: optimizing complex supply chains.

The common mistake is “copy and paste.” Every sector has its own characteristics. Trying to replicate an automotive assembly line inside a bank without adapting the principles to the local context is a recipe for failure.

4. My Practical Experience and the Mistakes I Have Witnessed

As a former VP of Toyota do Brasil, these are the most critical mistakes I frequently observe:

4.1 The “Toolbox Trap”

Many managers see Lean as a menu:
“Today we’ll implement 5S; next week we’ll do SMED.”

The mistake: using tools without a clearly defined problem to solve.
The result: tools become bureaucracy and stop being used as soon as supervision decreases.

The TPS perspective: at Toyota, we did not install an Andon because it was modern; we installed it because we needed problems to “scream” so they could be solved immediately. The tool is the means, never the end.

4.2 Neglecting “Respect for People”

This is perhaps the most serious mistake.

TPS is often represented as a house supported by two pillars (Just-in-Time and Jidoka), but its true foundation is respect for people.

The mistake: treating operators as extensions of machines whose only role is to follow the Standard Operating Procedure (SOP).

The TPS perspective: standards exist so operators can recognize deviations and propose improvements. When leaders stop listening to the people at the Genba, they waste the organization’s most valuable asset: human intelligence.

Lean is sustained by two inseparable pillars: continuous improvement and respect for people.

If employees believe Lean exists only to reduce costs or eliminate jobs, they will never genuinely collaborate in identifying waste.

The result is fear. And fear destroys Kaizen.

4.3 The “Island Kaizen” Myopia

It is common to find one highly organized production cell while the rest of the operation remains unstructured.

The mistake: optimizing isolated processes without considering the overall flow.
In many cases, increasing the efficiency of a single machine only generates more inventory, and overproduction is one of Lean’s worst forms of waste.
The TPS perspective: we must see the end-to-end flow (Value Stream). If an improvement does not help the product reach the customer faster, better, and with greater stability, it is merely an illusion of productivity.

4.4 Managing by Office Metrics (Lack of Genchi Genbutsu)

Many executives try to implement Lean by looking only at spreadsheets and dashboards in meeting rooms.

The mistake: making decisions based solely on averages and reports without seeing the real process.
The TPS perspective: throughout my journey at Toyota, I learned that the answer was always on the shop floor. If you do not go to the Genba to understand the root cause of the problem (Genchi Genbutsu), you are not solving anything; you are only guessing.

4.5 Fear of Stopping the Line

In the concept of Jidoka, every operator has both the right and the duty to stop the line whenever an abnormality is identified.

The mistake: leaders who prioritize volume over quality and “push” defects to the next stage just to avoid compromising the day’s target.
The TPS perspective: stopping the line today to solve the root cause prevents it from stopping tomorrow for the same reason.

Hidden problems are a cancer to productivity.

5. Conclusion

The Lean journey is a marathon, not a sprint.

Many companies still see Lean as a project with a deadline, when in reality it requires continuous cultural transformation.

Success does not come from the perfect application of tools or visual boards, but from a change in mindset among leaders and employees.

At Toyota, I learned that the real differentiator lies in discipline and humility to learn daily from one’s own mistakes.
The greatest challenge for companies is not learning Lean tools, but unlearning traditional management models.

TPS was not created to be easy; it was created to be disciplined.

And the greatest mistake of all is looking for shortcuts.

There is no such thing as “fast Lean.”

What exists is the daily construction of a culture where every employee becomes a problem solver.