1. The downstream process determines the purchase of the product in accordance with the exact amount stated on the billboard.
2. The upstream process produces the product in the exact number and order stated on the billboard.
3. If you do not see a billboard, you will not produce or carry the product.
4. All parts and materials must be accompanied by billboards.
5. Never send defective and incorrect products to the next production station.
6. When reducing the number of billboards, you should be very careful to avoid the problem of some shortage of inventory.