Lean Production Field Manual - Unit Production and Pull Kanban

Author: Sun Yabin
Publisher:
Publish Date: 2006-07-01
Features: In 1945, Ohno Taiichi was very surprised to learn that Japan's per capita productivity was only one-eighth of that of the United States. He had never imagined that the gap between Japan and the United States was so large. Where was the problem? He believed it wasn't that the Japanese were lazy. The reason was likely that there was some significant waste in their work. As long as this waste could be eliminated, productivity could grow tenfold or even a hundredfold. Based on this understanding, Toyota continued to identify and eliminate waste over the decades and finally achieved a hundredfold growth. In the process of fighting waste, Toyota gradually developed its own production system. Therefore, it can be said that "eliminating waste" is the fundamental concept of the Toyota Production System. The Waste Principle of Lean Production: Not all work has value. Any production that exceeds customer requirements in terms of equipment, materials, space, and labor is waste. These wastes are different, and at the same time, the relationships between them are intricate. One waste often leads to multiple wastes. Among all wastes, logistics is key. Starting with reducing inventory is a typical practice in lean production. The Waste Principle of Lean Production is based on Toyota's fundamental concept of "eliminating waste." This principle has three layers of meaning.
First Meaning: Not all work has value; many tasks are waste. What is waste? Any production that exceeds customer requirements in terms of equipment, materials, space, and labor is waste.
Second Meaning: The relationships between wastes are intricate and mutually derived. A leader of a company tried to eliminate transportation waste. He said, "Transportation is waste. I am preparing to double the size of the turnover boxes for transporting work-in-progress, so I can halve the transportation time." This approach is not advisable, because while eliminating transportation waste, the waste of work-in-progress increases. Therefore, the relationships between wastes are intricate, and if handled improperly, the hard-won solutions often create new problems. A company gradually increased its inventory, occupying a large amount of production space. They then built a new warehouse. After the warehouse was built, to facilitate operations, they purchased forklifts. After purchasing forklifts, they hired new forklift operators. From this, we can see that what started as inventory waste, due to improper handling, led to more and larger wastes.
Third Meaning: Based on extensive practical experience, logistics is key, and inventory waste is a signature waste. Here, inventory refers to all raw materials, work-in-progress, and finished products in the company. Why is logistics key? Because all activities at the work site revolve around logistics, and all waste and unreasonable activities will ultimately manifest in logistics. Poor management inevitably leads to logistics bottlenecks, and logistics bottlenecks inevitably result in large amounts of inventory. The awareness reform required to implement lean production includes: first, having a clear understanding of one's work goals and identifying the true value of one's work; second, recognizing all waste phenomena in the company's production process and clarifying the relationships between wastes; and third, grasping the key issue and actively guiding the company toward "zero inventory." First, let us theoretically explain what value is and what waste is. P15-16