Lean manufacturing is operating your facilities with the least amount of waste at the highest state of efficiency with the least amount of investment and the lowest number of employees, the highest state of quality, the shortest timeline from order to delivery of the finished products, that you neither over nor under produce, and that you deliver the products to your customer neither early nor late—just exactly on time.

Reducing changeover times is one way to eliminate waste and one area that contributes to a shop becoming lean. The keys to quick changeover are as follows:

Rethink the idea that machines can be idle, but workers cannot be idle.

The ideal setup change is no setup at all or within seconds.

Ensure that all tools are always ready and in perfect condition.

Blow a whistle and have a team of workers respond to each changeover.

Establish goals to reduce changeover times, record all changeover times and display them near the machine.

Distinguish between internal and external setup activities and try to convert internal to external setup.

I want you to see if you can reduce the changeover time on this punch press from four hours to two hours. This was a magical moment. Imagine if your client or your boss came over to you and asked that question of you and you knew that it had always taken close to four hours to do that changeover. What would you think? watched and studied various changeovers in the plant. A few days later Ohno came over again and Two hours is not good enough we need to lower it to 10 minutes.

With sitting in front of a punch press and watched operators change the molds. As we watched, slowly, light bulbs went off in our head and we found ways to reduce setups, virtually all setups at Toyota, from hours to less than 10 minutes.