5S -Seiri, Seiton, Seisou, Seiketu, Situke-

5S is a commonly used Japanese management concept in operations. However, we seem to emphasize preserving the initial “S” more than its original meaning. Instead of participating in a linguistic game with five words in Japanese and other languages that share the same initials and definitions, I prioritize the meaning.

🔹 Seiri 【整理】

“Seiri.” 【整理】 Taichi Ohno states in his book that “Seiri” means to discard unnecessary items. However, this is not a typical way to use “Seiri.” For instance, in 2024, an earthquake struck the Noto area of Japan. A media outlet interviewed a man who had lost his family. He stated, “I can’t 'Seiri' my emotions.” Is he trying to discard something unnecessary from his emotions? Something doesn’t add up.

Discarding unnecessary items is one way the Japanese utilize the concept, but it is not its typical application. It primarily means “to organize.” The first symbol, Sei 【整】, represents this meaning. Since the first symbol already conveys “organize,” the word must encompass more than that. The second symbol, Ri 【理】, signifies “science or logic.”

The combination of these two symbols can be interpreted as follows:

1️⃣ Organize based on science and logic.

2️⃣ Organize the scientific concepts and logic.

These definitions provide a clearer understanding of the meaning of “Seiri.” Often, we lack precise scientific or logical guidance to determine what is necessary and what should be eliminated. Consequently, due to human nature, we tend to hold on to as many things as possible, creating more Muda. Therefore, the first step is to define science and logic. This science and logic will be applied as standardized work, the essential foundation of “Seiri.”

A common mistake that often occurs is designing standardized work around the 5S. In other words, they implement 5S first and then standardize the work processes. In such cases, we see an operator taking a detour because someone has placed the materials in an inconvenient location. An operator was walking toward the tool, which was located far from its point of use. When the worker relocated an item to a more convenient spot, they were punished as a “5S violation,” rather than being recognized as part of a Kaizen initiative. They had to make such wasted movements because someone designed the 5S system without considering human work. TPS designs processes with respect to human work. True 5S does not force an operator to move unnecessarily.

5S represents the shadow of standardized work. “Seiri” means “Organize the shop floor according to the standardized work.”

🔹 Seiton 【整頓】

“Seiton.” The second word in the 5S, “Seiri-Seiton,” is a traditional Japanese proverb that is integral to daily life. My three-year-old son uses this phrase at his preschool. (I did not teach him this phrase because I knew it would be too complex for a three-year-old to grasp. Our understanding of “Seiri” involves organizing according to standardized work procedures. What defines standardized work for three-year-olds?) It is used daily, which is why it resonates with the Japanese. Hopefully, something similar exists in other cultures as well.

Ton 【頓】 is an interesting symbol. Taichi Ohno used a term called “Tonpuku【頓服】,” a medicine that takes effect immediately, to explain this symbol. However, it has additional meanings. The symbol signifies calming down. Thus, Tonpuku is a type of medicine used to alleviate symptoms with an immediate effect. Consequently, Ton 【頓】 has two meanings (relative to this topic);

1️⃣ Immediate utilization or effectiveness.

2️⃣ To calm down.

I know it's a strange combination of meanings. Still, by understanding the meaning of that symbol and the message Ohno tried to convey, I assert that the definition of “Seiton” is to organize without waste, using items that are readily usable and in stable condition. The materials and tools must be easily accessible for immediate use by the operator, eliminating Muda and ensuring efficient access. Furthermore, once the items are used, a standardized process is established to return them to their original condition easily.

On today’s shop floor, the popularity of 5S activities has led to many decorative cases and boxes. Although these containers may be visually appealing, they require extra movements from the operator, which undermines the purpose of 5S. Moreover, despite these elaborate items, we still see people firefighting to maintain the 5S system. 5S is not just tape on the floor. 5S is not merely the tools on the board with those shadows. 5S is a tool to eliminate Muri, Mura, and Muda. And once again, this is created by good standardized work.

A Muda-free shop floor represents the ideal state, and 5S should be the tool we use to strive for that perfect condition.

🔹 Seisou 【清掃】

Seisou is about cleaning, not just to make things tidy or shiny. It emphasizes preventing problems before they arise. TPS tools identify issues and promote problem-solving, placing a strong focus on avoiding the development of problems.

I had the opportunity to visit a factory with the former Toyota team leader. When he arrived, he complained that it was too dirty and began cleaning. Then a problem occurred: a pump broke. Following the safety protocol, the former team leader immediately opened the pump and found a foreign object inside. He told me, “This is why we must clean the plant.”

When we clean the shop floor, we uncover many items. Why do we have this inventory that has been sitting for a month? How did these nuts and bolts end up here? Why is there a paper that is supposed to accompany the products? What is causing this leak or noise from the machine? All these discoveries and questions that arise during cleaning create opportunities for improvement and learning. We should take action before these findings turn into problems for operations. And this is why “Seisou” is part of Buddhist training. They use cleaning as a process to reach enlightenment.

So, “Seisou” is about maintaining cleanliness to prevent problems and being proactive by learning from them. The management values the activities that contribute to a stable working environment.

🔹 Seiketsu 【清潔】

“Seiketsu” is known for maintaining the three conditions mentioned above. Additionally, there is another hidden key concept in this word, “Seiketsu.”

“That person is a 'Seiketsu' politician.”

This is another way to use the word “Seiketsu.” It does not imply that the politician is conservative. Instead, it suggests that the politician is honest or, more importantly, fair. “Seiketu” also means that an activity or a person’s characteristics and actions are pure, free from lies and deceit. There is a word called “Seirenkeppaku 【清廉潔白】,” which uses the same symbols, meaning absolute honesty or unsullied integrity.

“Integrity” is essential for maintaining the 3Ss. I considered two forms of integrity.

First, there's the task and the allocated time. Very often, the time and resources provided for cleaning are lacking. Even if there is a timeframe, the number of tasks exceeds the available time. 5S violations will occur in such an environment, and shop floor frustration toward management will increase.

The other type of “integrity” involves the actions taken when the 5S principles are violated. I observed a supervisor taping the floor around a pallet. I asked the supervisor, "Why are you taping around the pallet?" He explained that someone had left the pallet there and was afraid of being blamed, so he was taping the floor. I told the supervisor not to tape it because we didn't need the pallet. A couple of hours later, the supervisor returned angrily, informing me that the area had received bad feedback. I brought in the plant manager, and we began to problem-solve to understand why the pallet had been left there. Ultimately, we discovered that the pallets contained materials for which the incoming inspections were incomplete, exposing arbitrary decisions made by the quality acceptance team to the plant manager. Often, such problem-solving around 5S does not occur, leading to unfair evaluations. The supervisor should have had the authority to initiate problem-solving when someone violated the 5S principles. The organization should be held accountable for what happened. Instead, 5S reacted to a phenomenon on the shop floor, resulting in unintended consequences.

Seiketsu aims to maintain integrity.

🔹 Shistuke 【躾】

”Shitsuke” is discipline. But discipline of whom?

Often, we observe the connection of this discipline to the operators.

The focus of this discipline is the manager, not the operators. But what aspect of the manager’s discipline? The manager's role is to ask questions on the shop floor regarding 5S. A company provided trash grabbers to its managers to facilitate picking up trash. Is removing garbage the manager's responsibility in 5S? Absolutely not. Trash grabbers are not the appropriate tool for a manager. This reflects the CEO's criticism that 5S is the most expensive janitor they have ever hired. If the manager constantly picks up trash, they become the most costly janitor. While picking up trash is necessary for managers, it should only be done once. During that moment, the manager must ask the right questions, which should lead to eliminating the reasons why trash is left on the floor.

The right question can be tricky. The company distributing the trash grabbers to the managers asked, “How can trash picking be made easy for managers?” This is the wrong question. Some managers ask, “Why do ‘I’ need to pick up the trash?” and then add more janitors, incurring additional costs. Again, the wrong question. The right question is, “Why does this trash exist?” and continuously drives the organization to eliminate the need to deal with the trash and reduce costs. Often, the manager stops asking questions about the why, accepting the current condition. It is always essential that these questions lead to an understanding of the science and logic behind standardized work, the elimination of waste, preventive actions, and fairness. If the manager asks the right questions, then 5S will become a complete cycle that drives Kaizen in an organization.

In Taiichi Ohno's “Workplace Management,” there is a chapter on 5S. While the chapter title in the original Japanese version is “Seiri, Seiton, Seisou, Seiketsu, Shituke,” the English version omits “Shituke,” which translates to discipline. (Paragraphs about discipline are translated.) The reason for this omission is unclear. I suspect the translator couldn’t find a suitable translation for something that starts with an “S” and didn’t want to change the meaning, so it was left out of the title.

Each of the five words carries deep meanings. Let's focus on the meanings rather than the initials.

Seiri: Organizing the shop floor according to standardized work.

Seiton: Organizing effectively while reducing waste and creating a sense of calm.

Seisou: Cleaning to prevent problems from arising. Acknowledge the actions that foster prevention.

Seiketsu: Integrity.

Shitsuke: The management discipline of asking the right questions on the shop floor.