Just –in-time manufacturing is a demand-pull system that requires goods to be pulled through the system by present demand rather than pushed through the system on fixed schedule based on anticipated demand. Many fast-food restaurants, like McDonald’s use a pull system to control their finished goods inventory. When a customer order a hamburger, it is a taken from the rack. When the number of hamburger gets to low, the cook make new hamburgers. Customer demands the materials through the system. This same principle is used in manufacturing settings. Each operation produces only what is necessary to satisfy the demand of the succeeding operation. The material or subassembly arrives just in time for production to occur so that demand can be met. Thus, complementary to and part of the total JIT system is the concept of JIT purchasing. JIT operation
Requires suppliers to deliver part and material just in time for production. Supplier linkages are vital. Supply of parts must be linked to production, which is linked to demand. In a survey among manufacturers in the United States, 85 percent say that some or must materials, part, and components are supplied to them on a JIT basis. Thus, JIT inventory systems now appear to be extensively use.