In the late 1940's, Toyota started in the automotive business with the goal of making 50 to 100 cars per month. The process of stamping body panels was a barrier.
The typical car body had 300 stamped steel parts. To make these stampings, Toyota purchased three used presses in Detroit and shipped them to Japan. These presses required 24 hours to change a die. After a die change, it took less than an hour to stamp the parts Toyota needed for that month.
The manager, Taiichi Ohno, had an obvious problem. Making 300 different stampings each month required 300 set-ups, and with a 24-hour set-up, 300 days were needed. However, he had three presses, which provided, even if they were used seven days a week, only 90 days of capacity. At the time, Toyota could not afford to buy enough presses. So, Ohno was forced to focus on reducing set-up. With the mantra, " small lot sizes and quick set-ups," his people got die change set-up down to 2 1/2 hours.