Many pioneers of lean manufacturing or JIT traveled to USA to study the Henry Ford’s line assembly system. They studied the manufacturing system which made Henry Ford one of the richest of the planet. They studied the pluses and minuses of the system.
But, many Japanese manufacturers were more interested in supermarkets than Ford’s system. Sounds bad? It is true though. Lean manufacturing pioneers thought about the possibility of using the super market concepts in the manufacturing process that they are going to develop. It might not be possible to say lean manufacturing is born on the supermarket concept. But JIT operates more or less similar to the concepts of the super markets.
A supermarket never keeps large stocks in them. They will keep only the shelf full and when the goods are being removed from the customer, it will be detected ad the shelves will be replenished daily or twice a day. The important concept behind this system is not having large stocks and continuous replenishment based on the consumption. This will give supermarkets large floor space savings, less wastage and ability to react for the customer requirements.
This is what happens in JIT manufacturing. Goods are produced only when they are required. Therefore there is no requirement for the stocks. Raw materials are purchased in small batches, when they are required. Then the goods are produced with a continuous flow. Then the finished products are distributed to the customers in small batches, continuously. This means, no wastages in the form of opportunity loss for the capital, reduced quality defects, floor space savings, higher flexibility and shorter lead-times.
This process will be stimulated by the customer demand. Customer requirement will pull the product from the manufacturer. Don’t you see a big similarity between lean manufacturing and supermarkets?