I have been reading several posts about Lean and Six Sigma. The way the two philosophies apparently differentiate is that Lean is all about eliminating waste, and Six Sigma is all about eliminating variation. As with many concepts in Eastern philosophy, things appear simple at first sight, and as we learn more about it, the concept gets deeper and deeper. In today’s post, I will look at the Toyota Production System in the light of “waste”.

Waste (Muda):

The Japanese word for waste is “muda”. Muda literally means no value. Mu = no or lack of, and da = value. The idea that Toyota Production System is based on the principle of eliminating waste was put forth by Taiichi Ohno, the father of Toyota Production System. Ohno identified seven types of wastes as follows;

• Waste of overproduction
• Waste of time on hand (waiting)
• Waste in transportation
• Waste of processing itself
• Waste of stock on hand (inventory)
• Waste of movement
• Waste of making defective products.

A close review of these wastes shows that many of these wastes are interconnected. If you have inventory, you will also have transportation. Waste of processing can also lead to waste of movement. Waste of overproduction is sometimes called as the mother of all wastes since it can lead to all of the other types of wastes. Several practitioners have identified more types of wastes, of which the most popular is the “under utilization of human talent”.

Let’s Go Deeper:

I do not agree with the generalization that lean is about eliminating waste. Toyota speaks about 3 “Mu”s. They are as follows;

• Muda = waste
• Muri = overburden
• Mura = unevenness

Muda:

Things get complicated when we learn that Toyota uses Muda in 3 different meanings. The Japanese language has several writing systems. Muda has roots in Chinese language. Japanese can write Muda in 3 different writing styles to add particular nuances.

Muda in kanji (based on Chinese scripts) means waste that was created by existing management policies. Muda in hiragana (based on native or naturalized Japanese words) means waste that cannot be eliminated right now. Muda in katakana (based on foreign words or words used with emphasis) means waste that can be eliminated immediately. (Source: Kaizen Express, Toshiko Narusawa and John Shook)

Taiichi Ohno defined the Toyota Production System as follows;

“The fundamental doctrine of Toyota Production System is the total elimination of waste”.

Muri:

Muri literally means “unreasonable” in Japanese. Mu = No or lack of, and Ri = reason. Both muda and muri can be explained in Japanese as a “lack of something” or as “no + something”. Muri also has several nuanced meanings in Japanese. “Muri suru” in Japanese means “to take things too far” or “to overdo”. In TPS, muri refers to overburdening the operator so that it can result in injuries or defective products. This is akin to saying work harder to produce more products while not improving the process. The standard work is often used as a means to tackle muri.

Mura:

Mura is defined as “uneven”. I have not seen mura explained as a “lack of evenness” (Mu + evenness) in Japanese. For example, the unevenness is in how we manufacture products. We should produce products so that we can meet the customers’ demands. From a producer’s standpoint, producing product of one type makes the most sense since it maximizes efficiency. This is akin to the famous Ford quote “as long as it is black”. However, each customer is unique. He may want “red” instead of black. He may want a different model than what you want to make. The unevenness is in how the units are being produced without keeping the end picture in mind. TPS utilizes both kanban and heijunka to level production.

Taiichi Ohno defined the Toyota Production System in light of this as follows;

“The goal of the Toyota Production System is to level the flows or production and goods.”

The 3 Mu’s:

The keen learner can see that muda, muri and mura are closely intertwined. Toyota has even defined muri and mura as two forms of muda!

“Both mura and muri are thought of as types of muda, or waste, and should be eliminated.”

Mikio Kitano, former President of Toyota Motor Manufacturing of North America Inc, has identified the order to approach the 3 Mu’s for a new process. (Muri -> Mura -> Muda)

“First, Muri focuses on the preparation and planning of the process, or what can be avoided proactively. And, then, Mura focuses on implementation and the elimination of fluctuation at the operations level, such as quality and volume. The third — Muda — is discovered after the process is in place and is dealt with reactively. It is seen by variation in output. It is the role of Management to examine the Muda, or waste, in the processes and eliminate the deeper causes by considering the connections to Muri and Mura of the system. The Muda – waste – and Mura – inconsistencies – must be fed back to the Muri, or planning, stage for the next project.

The continuous cycle of self-examination allows for the outcomes to continuously improve. This brings in Management’s responsibility:

• to provide and improve a flexible system, and
• to connect the workforce and the customer.”

My thoughts:

As I have already stated, I do not believe in the generalization that TPS or Lean is about the elimination of waste. This makes it a tool based system. TPS is a holistic management system. Once we look deeper at how the “waste” is viewed, we understand that this does not mean just seven types of waste.

There is a counter-intuitive aspect to muri. Taiichi Ohno was famous for asking to produce the same amount of products by utilizing fewer employees. He would say to remove one operator and then try to meet the same production numbers. Would this be not adding muri? My understanding on this is that Ohno was very good at identifying all of the non-value adding activities in the process. He was able to see that the production can be run with fewer operators. He wanted to challenge the supervisor and the operators in kaizen by studying their standard work and improving their process.

I will finish off with a zen story about “mu” that I like a lot. This story is similar to this post in that it appears straightforward at first.

A monk asked Joshu, “Does a dog have the Buddha-nature or not?”

Joshu replied, “Mu.”

In this koan/story, Joshu is breaking the conventional thinking of the monk. In Mahayana Buddhism, the Buddha-nature is present in all beings including humans and dogs. The answer to the monk’s question should have been “yes”. But the monk’s perspective of nature of existence was one-sided and tunnel-visioned. Joshu challenged this and broke the monk’s mold of thinking by saying the answer “no”.

If Ohno was alive today and one were to ask him whether TPS was about eliminating waste, the master might have replied, “Mu”.

Always keep on learning…

In case you missed it, my last post was Respect for Humanity in the Light of Quality Control (QC).

I talked about the two conceptual houses of Toyota last week. In today’s post we will look JIT and Jidoka, the two pillars of the Toyota Production System house. The two pillars of the TPS house are actually based on the ideas of Sakichi Toyoda (Jidoka) and Kiichiro Toyoda (JIT). Ohno built his production system on the shoulders of these two giants.

Sakichi Toyoda, father of Kiichiro Toyoda, founded Toyoda Automatic Loom Works in 1926. Sakichi was an inventor and considered to be an eccentric (Source: Fifty Years in Motion, Eiji Toyoda 1985). His greatest invention was perhaps the Type G Automatic Loom, a non-stop shuttle change automatic loom. Sakichi sold the license to the Platt Brothers and Co. in England.

There is a great story about Sakichi Toyoda in Eiji Toyoda’s book, regarding the automatic loom invention. The looms used to be manually operated and were made of wood. Sakichi wanted to create a loom that ran on power. The best power source in his days was steam. He purchased a used steam engine to understand how it worked and to use that to power his looms. The looms however did not move because the steam kept leaking. Sakichi took the engine apart and found that the problem was worn down piston rods that caused the steam to leak. This would be an easy fix to have new rods turned down on a lathe. Sakichi, however, did not have access to a lathe. So Sakichi and his team spent a whole night manually filing the rods down! When they put the rods in the engine, it worked.

Kiichiro Toyoda, Sakichi’s son, formed an automotive division under Toyoda Automatic Loom Works. He later spun this off, and created Toyota Motor Company in 1937. He calculated that with a population of one hundred million people in Japan, a car-to-people ratio of 1:10 would equate to ten million cars. If there was a 10 percent replacement per year, this would equate to one million cars. He thought that this was a good reason to start a car company.

Just-in-Time:

Kiichiro Toyoda, who founded the Toyota Motor Corporation, had come up with the idea of making the right parts at the right time, and in the right amount. In those days, the norm was to use a lot production system. This is based on producing parts according to what the operation can produce. Thus, there was a disjoint between what is actually needed, and what the operation produced. The operation tended to produce as much as it could to be efficient. This led to high inventories, which led to large stock rooms to store these inventories. Kiichiro understood that this automatically increased the cost to run the business, something that Toyota struggled with tremendously in the beginning. He decided to switch over entirely to a flow-type production system. He called this the “just-in-time” concept:

“I believe that the most important thing is to ensure that there is neither shortage nor excess, that is, to ensure that there is no excess labor and time for the designated production. There is no waste and there is no excess. It means not having to wait for parts to be circulated around. For Just-in-Time, it is important that each part be ready ‘just in time’. This is the first principle of increasing efficiency.” (Source: July 1938 issue of Motor, Toyota-Global website)

“Just make what is needed in time, but don’t make too much.” (Source: Fifty Years in Motion, Eiji Toyoda 1985)

Kiichiro wrote a four inch binder manual detailing his ideas for JIT. His ideas were used at Toyoda Automatic Loom Works, which is where Taiichi Ohno first joined Toyota at. Kiichiro tried to implement this at the Koroma plant, Toyota’s second automotive manufacturing facility. It did not take hold at the Koromo plant due to part shortages when the war with China (2^nd Sino-Japanese War and World War II) expanded into the Pacific. It is said that Eiji Toyoda, Kiichiro Toyoda’s cousin, requested Ohno’s help to implement Just-in-Time at the Koroma plant.

“Mr. Ohno”, Eiji said, “this plant looks like a storeroom. Can you do something to take care of this?” Eiji wanted to pleasantly surprise the big man (Kiichiro Toyoda) and show that Just-in-Time was already in operation at the Koroma plant. (Source: The Toyota Leaders, Massaki Sato.)

It should be noted that Eiji Toyoda was a strong supporter of Taiichi Ohno, and stood behind him when he was developing the system. In Taiichi Ohno’s words – “Our approach has been to investigate one by one the causes of various unnecessaries in manufacturing operations and to devise methods for their solution, often by trial and error.”

Ohno would later on create the Kanban system to incorporate the Just-in-Time philosophy.

Jidoka:

Jidoka in Japanese stands for “automation”. Toyota added an extra character representing “human” in Japanese to mean “autonomation” or “automation with a human mind”. In Japanese, both words can be expressed as “Jidoka”. The word autonomation comes from joining “autonomous” and “automation”.

There are two approaches to autonomation at Toyota. The first approach is to separate the operator’s work from the machine’s work. This means to treat the operator as being independent of the machine, or in other words the operator can operate multiple machines simultaneously. The norm had been to have one operator dedicated to one machine only. The operator had to watch the machine work, while not creating value at the same time. In his mind, he was creating value by simply watching the machine operate. The second approach is to have the machine detect an anomaly and stop by itself. This would prevent the machine from producing more defects. Additionally this will also force the operator to fix the problem immediately to maintain the flow of the process. Both of these ideas belonged to Sakichi Toyoda, father of Kiichiro Toyoda. His Type G loom was an automatic loom that stopped on its own when any of the threads broke. Thus, the loom did not continue producing defectively. Sakichi had successfully implemented the two approaches at the Toyoda Automatic Loom Works. At the Toyoda Automatic Loom Works, one operator could operate 25 automatic looms at the same time.

Soon after World War II, Kiichiro declared the company goal of catching up with America’s productivity within 3 years. In order to do this, Taiichi Ohno used the idea of having an operator in charge of multiple machines at a time. This increased the productivity by many fold. However, this came with its own problems. The machines were not aligned properly so that when the machine was done with its operation, instead of stopping it kept on making parts. Additionally, if the machine malfunctioned, it continued making defective parts. Thus, even though the productivity increased, it put a strain on process flow and quality.

In order to counter the flow problems, Ohno utilized machine layout and limit switches so that the machine stopped producing when the required amount of parts were produced. For the quality problems, Taiichi Ohno utilized the second approach of Jidoka, to have the machine stop production on its own when there is a problem or when the required quantity is made. This idea of Jidoka is to build in quality, ensuring that defective parts are not passed to the next station. This theme evolved into empowering the operator and giving him the authority and responsibility to stop the line if they identified a problem on the line. The operator would pull on the andon cord which would trigger an audio and visual signal for the lead or supervisor to come and help in fixing the problem. If the problem is not fixed in the allotted time, the entire line will stop until it is fixed.  Jidoka develops the operators to look for problems and then solve it. Jidoka thus evolved into a strong training tool and an employee empowerment tool for Toyota. Jidoka placed a spotlight on problems.

Final Words:

Ohno created the Toyota Production System based on the ideas from Kiichiro Toyoda (Just-in-Time) and Sakichi Toyoda (Stop on Defect).  It should be noted that all of the “tools” in TPS were created for the two pillars to work effectively. At first, the goal of TPS was to increase productivity to catch up with Detroit. However, as the productivity increased, it became necessary to maintain quality, and to ensure that the employees are challenged to continuously improve their processes.

I will finish off with an Ohno story. This was told by Michikazu Tanaka in the 2009 book “The Birth of Lean.”

Ohno was very interested in the Supermarket system that was in America. Ohno explained with passion to Tanaka how Toyota can utilize the concept of a Supermarket. Tanaka could not quite grasp the concept since supermarkets were still a foreign concept in Japan, where the shopkeepers fetched the items for the customers. Tanaka was amazed that the shopkeepers would let the customers freely pick what they want from the display, and pay as you go out.

“What would happen,” he asked Ohno, “if someone went in and ate a bunch of food without paying?”

Ohno was stumped and he did not have a good answer for Tanaka. He thought for a while, and said “I suppose that Americans are a people of integrity and they would know not to do that!”

Later on when Ohno implemented kanbans, he told the people on the floor “Kanban is like money; if you take out parts without kanban, you are stealing the parts”. (Source: The Evolution of a Manufacturing System at Toyota, Fujimoto)

Always keep on learning…

In case you missed it, my last post was The Two Houses of Toyota.

In my last post, I talked about being like a Samurai warrior at the gemba. Today, I am posting about being an amateur at the gemba.

The word “amateur” has roots in the Latin word “amare” which means to love. “Amateur” used to mean someone who is pursuing something out of pure love or passion. Once the word “amateur” entered the English language, it got associated with a negative connotation. Today being an amateur means that one is a mere hobbyist, and may lack experience and knowledge. Today, its meaning does not encompass the meaning of passion that it once used to have.

Taiichi Ohno was a man of passion and was new to the automobile world when he heard Kiichiro Toyoda, the then leader of Toyota, talking about the need for Toyota to catch up with American car manufacturing in three years to survive. Ohno was not an expert in auto manufacturing, and the Toyota Production System did not exist at that time. Ohno called himself a “layman” when it came to the auto industry. However, he did have a tremendous amount of love and passion for the manufacturing world. He was an amateur in the classic and modern sense.

Taiichi Ohno- What would Ohno Do?

Taiichi Ohno graduated from the Department of Mechanical Technology of Nagoya Technical High School in the spring of 1932. He then got a job at Toyota Textiles through his father, who was an acquaintance of Kiichiro Toyoda. He later got transferred to Toyota Motor Company in 1943, when Toyota Textiles was dissolved. At this time, it was declared that the Japanese worker’s efficiency was only 1/9^th of that of an American worker. Kichiiro Toyoda gave Toyota the clear vision of catching up to America in three years.

Ohno correctly concluded that the high efficiency of the American operator was not due to him exerting ten times more physically than the Japanese operator. His only logical explanation was that there was a lot of waste in what the Japanese operator was doing. Ohno started experimenting and began planting the seeds of Toyota Production System (TPS). This was where the passion or love of the “amateur” came in. The amateur was not afraid to fail. Each step was a learning step for him. In my eyes, the turning point of TPS came when Ohno realized that he can have one operator take care of more than one machine at a time. The norm in those days was that one operator managed only one machine. The operator was not doing anything while the machine was operating. Ohno put the operator in charge of more than one machine. He had to ensure that the labor content remained the same. The operator was not being required to work harder! Ohno instead focused on the flow of operations. The machines were operated in the order as dictated by the flow of operations. In Ohno’s words;

The first step was to establish a flow system in the machine stop.

Ohno proposed to implement work improvement first, and then to do facility improvement. Ohno experimented with different layouts to improve the flow. Some of them are shown below (U-shape/Bracket, Triangle, Square and Diamond).

Ohno also introduced the idea that to manufacture beyond what is needed is to create waste (waste of over-production). He also introduced the idea of using kanban as a way to ensure a pull system and continuous flow.

One would imagine that Ohno’s ideas would be welcomed with open arms. Instead, he faced a lot of resistance. In fact, his ideas were first called “Ohno’s System” instead of “Toyota Production System”. Gandhi famously stated the following;

“First they ignore you. Then they laugh at you. Then they fight you. Then you win.”

This was true in Ohno’s case. Ohno was called “Mr. Mustache”. The operators thought of Ohno as an eccentric. They used to joke that military men used to wear mustaches during World War II, and that it was rare to see a Japanese man with facial hair afterward. “What’s Mustache up to now?” became a common refrain at the plant as Ohno carried out his studies. (Source: Against All Odds, Togo and Wartman)

His ideas were not easily understood by others. He had to tell others that he will take responsibility for the outcomes, in order to convince them to follow his ideas. To his credit, he taught his ideas at the top and bottom simultaneously.

Ohno could not completely make others understand his vision since his ideas were novel and not always the norm. His style of production was not being practiced anywhere. Ohno was persistent, and he made improvements slowly and steadily. He would later talk about the idea of Toyota being slow and steady like the tortoise. Many of his ideas were based on trial and error, and were thus perceived as counter-intuitive by others. Ohno loved what he did, and he had tremendous passion pushing him forward with his vision. For this reason, Ohno was truly an “amateur”.

Final Words:

I have cited the example of Ohno, the father of Toyota Production System, to propose that one should try to be like him, an amateur – one who has tremendous passion and love for what he does and one who does not mind trying out his ideas even if they might fail. I will finish off with a story I read about Ohno,

As I mentioned above, Ohno’s methods were counter-intuitive in nature. Ohno wanted to increase productivity, and yet not over produce! Ohno in fact called Over-production as the biggest waste of all.

Ohno had started implementing Just-in-Time in the plant. The operators became insecure with this. They felt secure having extra in-process inventory so that they can keep working if there were line stoppages.

Ohno understood this, and became angry about this. He decided to combat this by making the operators take the unneeded material home with them.

“Since the company does not need these things”, he would tell the men as he filled their arms with parts at the end of the day, “you must take them home.”

(Source: Against All Odds, Togo and Wartman)

Always keep on learning…

In case you missed it, my last post was Be a Samurai Warrior at the Gemba.

Taiichi Ohno is the father of Toyota Production System. Lean Manufacturing is based on Toyota Production System. The term “Lean” was coined by John Krafcik in his MIT Sloan 1988 Fall paper “Triumph of the Lean Production System”. His terminology was “Lean Production” or simply “Lean”. He noted that;

“Plants operating with a “lean” production policy are able to manufacture a wide range of models, yet maintain high levels of quality and productivity”.

There have been many discussions about whether “Lean” is the correct terminology or not. Lean is supposed to have a negative connotation with it. There is a tendency to assume that Lean indicates reduction – reduction in inventory, reduction in cycle time, reduction in costs etc.

I was pleasantly surprised when I came across Taiichi Ohno’s thoughts on “Lean” Management. As indicated in my last post, Ohno started a consultancy group soon after leaving Toyota. This group was called the New Production System Research Association. Isao Shinohara wrote a book on this called “New Production System – JIT Crossing Industry Boundaries”, in 1985. The main theme of this book is that the TPS ideas are applicable across multiple industries. This book also had a section with an interview with Taiichi Ohno.

Limited, Not Leaner, Management:

In Ohno’s words;

“The idea is to produce only what can be sold and no more. The idea is to limit, not necessarily to reduce, the quantity. The important thing is to keep production costs low whle limiting the production level. It is meaningless to say that producing 15,000 units will reduce production costs when you can only sell 10,000 units.”

He continues;

“The essence of limited management (genryo keiei) and limited production (genryo seisan) is to produce what can be sold at the lowest possible cost.”

My favorite section of the interview was when Ohno was asked about reducing or eliminating inventory.

“Shinohara – Many people think that Toyota Production System is a method for reducing inventory or eliminating inventory altogether.

Ohno – That is not right. I’ve said this so many times, but people don’t seem to understand. The Toyota production system is a philosophy of changing the production and management flows.”

Analogy of a Boxer:

Taiichi Ohno compares limited production to the regimen of a boxer in his book “Workplace Management”. The boxer has to be in a specific weight classification. If he misses a few training sessions and he puts on weight, he can no longer compete in his class. He would then have to diet to slim down and maintain his weight. This is akin to a company trying to reduce inventory. If he loses more than his intended weight, he will run out of energy and lose the fight. This sort of slimming down is undesirable. Ohno advises against going on a diet for a company without thorough understanding. He calls it a dangerous idea to trim down so much that the essential meat of the company is cut into.

Always keep on learning…

In case you missed it, my last post was “Don’t Strive for Perfection – 60% is good enough”.