Just In Time Production 4️⃣ Ma 【間】
Taiichi Ohno described Just In Time as “ちょうど間に合う [Choudo - Mani - Au]” in Japanese.
Choudo = Just
Au = Fit, match
The tricky one is this concept of “Ma【間】.”
The Japanese concept means “Space, Gap, Pause, or Timing.” It is highly cognitive and not defined. It has some energy between the two objects. It depends on the situation or the relationships.
What does your factory fill with when there is a “Ma【間】”? Materials or trust?
When I think about “Ma,” I imagine the Samurai fight in comic books.
Two samurais are facing each other, slowly moving close to each other.
One makes a cynical smile and says, “You entered my “Ma.”
Swish. The attack is made.
The truth is there is no definition of “Ma.” This is strange thinking. When I think about the samurai’s fight, it seems that there is a range that the attack can reach. It is the length of the sword plus the length of the arm. But the art of the sword is not that simple. Depending on the skill of the swordsman, the attack range can change. The more experienced you are, the more extensive the range will be. The size of the “Ma” depends on the swordsman's skill.
This undefined scope of “Ma” explains why my coach was reluctant to define the target amount of inventory on the line side or the Just In Time. If we did define the quantity, that became a goal. Once we accomplish that goal, will we continue to challenge ourselves to improve more, or will we satisfy and stop going further? Like the samurai sword fight, we should perfect the “Ma” as much as possible. There is always “room” for improvement.
This “Ma【間】” exists in business. The business has many “Ma【間】,” typically filled with inventories. It’s human behavior. And why?
“Ma【間】” is used to describe human 【人間】 or humanity 【人間性】.
This is strange because the symbol 人 already means human. There is no need to add “Ma【間】.” When these combination【人間】of symbols were used, it originally meant the world or the society. Yet, as we understood more about humans and how we are not separable from our surroundings, the symbols started to represent humans. Humans are part of our surroundings, while the surroundings are part of us. This is not Japanese or Eastern philosophy. Western philosophies have similar thinking.
Typically, we want to surround ourselves with materials when there is negative energy. It is to protect ourselves from some harm to damage us. Inventory is a typical form of such negative relationships.
Sales want inventory since they don’t trust the production to be on time.
Each production processes keep inventories because of the doubt that other processes will operate stably or the delivery will be on time.
The factory builds warehouses for incoming materials since they suspect the suppliers will fail.
Inventory is a sign of some negative relationship energies among the parties.
On the other hand, Just In Time production is a system built on mutual trust. This mutual trust is built on mutual responsibilities, which is typical in the form of standardized work. When times of crisis, mutual support will be required. Without such trust, Just In Time production will fail.
Very often, I ran into meetings where a manager was faced with many parties reporting that inventories are necessary with a big smile. “It helps all of us.” But I always feel that smile as cynical a sign of something negative. A manager must think deeper about the root cause, which is not easy to overcome. Yet, not something that the manager should ignore because it will erupt eventually.
In Japanese Sword training, there is training to understand the “Ma【間】.” A student continues to try to attack the teacher. The teacher continues to evade without the actual counterattack. As this goes on, the student recognizes that he needs to use all it might otherwise reach the “Ma【間】.” Just In Time is like having this training everywhere all the time.