Waste Not, Want Not:
Some Thoughts On Lean Thinking

By Anthony Akin
Manager, Lean Six Sigma

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What we call lean thinking has largely originated in the work of Taiichi Ohno. He is considered the father of Toyota's methodology, The Toyota Production System, now identified as lean manufacturing.

Ohno began as an employee of the Toyota family's Toyota textile business, then moved to the motor company in 1939. He gradually rose through the ranks and became an important executive. His work is not only a significant foundation for Toyota's ultimate great success; it has had great impact on business throughout the world.

Ohno had a simple belief: "Costs do not exist to be calculated. Costs exist to be reduced."

He concentrated on the improvement of productivity through the elimination of wasteful behaviors. He referred to these as: insufficient standardization and rationalization, which creates waste (Muda), inconsistency (Mura), and unreasonableness (Muri) in work procedures and work hours. These eventually lead to the production of defective products.

Muda (waste) has seven basic configurations:
1. Waste of overproduction
2. Waste of time on hand (waiting)
3. Waste of transportation
4. Waste of processing itself
5. Waste of stock on hand (inventory)
6. Waste of movement
7. Waste of making defective products

If the goal is the complete elimination of waste, then waste must be looked at comprehensively and at length. This requires complete analysis of waste.


"When thinking about the absolute elimination of waste, keep the following points in mind: Improving efficiency makes sense only when it is tied to cost reduction. Look at the efficiency of each operator and of each line. Then look at the operators as a group, and then at the efficiency of the entire plant. Efficiency must be improved at each step, at the same time, for the plant as a whole."

One way of not only eliminating waste - but, in some broader sense, getting to the bottom of troublesome situations is to keep asking the same simple question: "Why?"

In the case of a machine stopping when it was not supposed to, Ohno teaches that we should repeat "Why" at least five times and have the answer to each "why" drive the next question:

Why did the machine stop?
There was an overload and the fuse blew.

Why was there an overload?
The bearing was not sufficiently lubricated.

Why was it not lubricated sufficiently?
The lubrication pump was not pumping properly.

Why was it not pumping properly?
The shaft of the pump was worn and rattling?

Why was the shaft worn out?
There was no strainer attached and metal scrap got in.

"Repeating why five times can help uncover the root problem and correct it. By asking why five times and answering it each time, we can get to the real cause of the problem, which is often hidden behind the obvious symptoms."

Taiichi Ohno started out in a world where Henry Ford's Detroit manufacturing plants were the acknowledged leader in productivity. Look at where we are today, when American and Japanese manufacturing methods are compared. Ohno's philosophy and the work that he did explain much of the difference.

To learn more about Taiichi Ohno and his theory, consider reading his books:
Toyota Production System: Beyond Large-Scale Production, Productivity Press
Workplace Management, Productivity Press