For our last full day in Japan, we left the modern manufacturing world to catch a glimpse into Japanese history and explore their rich traditions. This included a visit to a samurai house and spending the night at a traditional Japanese Inn. Although this experience, along with touring a Japanese castle, did not seem to directly relate to learning about lean manufacturing in Japan, it did end up providing some extremely valuable insights into the Japanese culture that I believe greatly influences the thinking found behind the principles of lean manufacturing.
For example, our tour of the samurai house was like stepping back in time. The overwhelming sense of honor, loyalty, protection and service for the good of the people and county was deeply felt as our tour guide revealed the details of the life of a samurai. This life was a simple one, centered on service above all else. To imagine that I was now walking across the same floor as this noble warrior and his family was an incredible feeling. By the way, samurai houses were located next door to the lord of the region for instant service and close communication.
I also learned a great deal about the samurai sword and how it was made. This caught my attention as I enjoy learning about history and basically, I am a manufacturing geek at heart. The making of a samurai sword is really a manufacturing marvel of perfection. To manufacture a light weight and extremely flexible sword to tolerances of .00001" without the aid of modern CNC equipment, computers or even basic temperature control devices is completely amazing to me.
From what I learned, this traditional manufacturing process dates back over 1000 years, performed by the skilled hands and knowledge of a master sword craftsman. The steel to construct the blade was heated, folded and beaten by hand with a hammer to a thickness of .00001". This steel layer was forge welded to another layer of steel, repeating the process of heating, folding and forming by hand. This process was repeated over 30,000 times with each layer .00001" thick. This successful method required to make a samurai sword involved ritual and most of all repetition. Sounds a lot like the power of standard work to me.
I was told, to insure consistent quality, that the sword maker used the color of the morning sun as his guide to the exact color needed when heat treating the steel. This visual guide helped establish an extremely accurate heat treat process. The end result was a willow-like, lethal weapon weighting less than 3 lbs, a weapon made by hand to high quality standards even compared to modern manufacturing standards.