The new crown epidemic is testing all aspects of the economy and society of the United States. Even on the issue of toilet paper, one of the necessities of people’s life, the United States has not delivered a satisfactory answer sheet, thus exposing the shortcomings of the industrial chain. < / P > < p > in the early stage of the global outbreak, the news that the United States, Japan and other countries had sold out of toilet paper was on the front page several times. The public’s concern is not groundless. The epidemic has been in full swing in the United States for more than five months, but the supply of toilet paper in the United States has not returned to normal. < / P > < p > the inventory of merchants still can’t keep up with everyone’s demand. On Amazon’s website, most toilet paper prices are still not returning to normal. Some sellers ask $45 for a dozen of toilet paper, about three times the usual price. If you place an order in a supermarket chain such as target, you still can’t receive it within a week. < / P > < p > although most supermarkets in North America have resumed the supply of toilet paper, and the shelves are no longer empty as before, some supermarkets still set a quota for each person to avoid being out of stock again. < / P > < p > this starts with the concept of lean manufacturing, which originated from the Japanese automobile industry in the 1970s. Lean production refers to timely manufacturing, eliminating failures and all waste, trying to achieve the goal of zero defects and zero inventory, so as to maximize profits. After the rise of the concept of < / P > < p > in Japan, it has been widely used in manufacturing, retail and other fields in the United States. Enterprise executives try to solve the problem of over bloated mass production in the United States by means of lean production. Before that, manufacturers would normally store raw materials and parts in warehouses for months, increasing costs. When enterprises find that lean production can significantly improve profits, they naturally choose this method. Profit significantly higher than the level of peers can also make enterprises more favored by capital, so it has been warmly supported by enterprises and investors. According to statistics, keywords like “inventory reduction” or “lean” were mentioned at least 550 times in the financial report conference call of S & P 500 companies last year. In 2006, Wal Mart cut its inventory cost by 6.5 billion dollars. Wal Mart rules that if suppliers deliver goods too early or too late, it faces a fine of about 3% of the total order amount. The direct result of lean production is that manufacturers only order just enough raw materials to keep the production line running normally. The transportation tools they own are just enough to transport the goods in a day or a very short period of time, and the manufacturers only keep the inventory just enough to fill the shelves. Many companies directly reduce production capacity or reduce inventory capacity. < / P > < p > under normal circumstances, this method achieves high efficiency, low cost and maximization of profit margin. However, when natural disasters, pandemics and other unexpected events occur, the disadvantages of lean production are reflected. Although lean production was first proposed, manufacturers were also encouraged to develop a comprehensive filing plan to deal with unexpected situations. However, as far as the current situation is concerned, due to the ultimate pursuit of profits, most companies completely ignore this point. Due to the large volume and high storage cost of toilet paper, lean production is used to the extreme in toilet paper manufacturing industry. Procter & Gamble, a large producer, once closed some production lines in the early 2000’s. This is the main reason why toilet paper has been out of stock for such a long time in countries such as the United States. < / P > < p > at ordinary times, all production machines, packaging machines, trucks and other delivery tools of the manufacturer are in the state of close to full load operation. When the demand suddenly increases, the operation of each link is far from meeting the demand, and the production materials such as trucks are in short supply, leading to the whole industrial chain even lagging behind even under normal conditions, the output is lower, and the retailers get less inventory. < / P > < p > it is also unrealistic for manufacturers to expand production as soon as possible. It takes several years to assemble the core parts of the machine required for making toilet paper and high cost. At present, manufacturers do not have any plans to expand production, because the construction of new factories requires a large amount of investment. If the long-term growth of market demand is not anticipated, the increase in capital is not worth the loss for the enterprise. In the rush buying tide, manufacturers can only increase their output by working overtime and vacating other production lines, but the production capacity is still limited. According to the Wall Street Journal, Georgia Pacific paper products manufacturing company in Georgia could only increase production by 25% at most, which was unable to meet the demand of customers at that time, which increased by five times or more than ten times. < / P > < p > at the beginning of the outbreak, not only toilet paper was sold out, but also a series of products such as hand sanitizer, kitchen paper and disinfection wipes were out of stock, and the masses fell into panic buying tide. What’s worse, masks and some food are also facing an extreme shortage of core materials in the epidemic situation, making it even more difficult to fight the epidemic. People’s daily life and even health and safety have been greatly affected. < / P > < p > the problems exposed in the U.S. manufacturing industry are still unresolved, which means that when the next unexpected attack comes, the industrial chain will still face a severe test. If you can’t buy toilet paper, it’s just inconvenient for your life, and it won’t cause too serious consequences. The key is, if the next time out of stock is not toilet paper, but food, medicine and other life-saving materials, how should American society respond?