A production system that makes and delivers exactly what is needed, exactly when it is needed, and exactly in the quantity needed. Just-in-Time and jidoka are the two pillars of the Toyota Production System. Just-in-Time is founded on heijunka, and it consists of three elements: the pull system, branch time and continuous flow.
Just-in-Time seeks the total elimination of all waste to achieve the best possible quality, the lowest possible cost, the minimum use of resources and the shortest possible production and delivery times. Although the principle is simple, it takes discipline to implement it effectively.
The idea for Just-in-Time dates back to the 1930s and came from Kiichiro Toyoda, the founder of the Toyota Motor Corporation. Taiichi Ohno said his first attempts to put Just-in-Time into practice were from 1949-1950, when he was manager of the machine shop at Toyota's main plant.