Toyota and Mr. Taiichi pioneered this method back in 1970. Back then, Toyota had rare materials and difficult geographic conditions (80 percent of Japan's topography is mountains). The expensive land price makes Mr. Taiichi Ohno develop a solution to tackle these problems.
Just in time inventory synchronized the material purchase from suppliers with the production schedule. This method is quite the opposite of just in case method which anticipates the rise of customers' demands by stocking enough supplies in the warehouse. With just in case inventory, materials purchased when only there's a demand from customers.