Shingo's insight: separate internal end external to reduce setup by half

Let’s look at what Shingo discovered about setting up stamping presses. He spent time observing the setup process, and had the great insight that there were two kinds of activities taking place: Those that required the press to be stopped in order to be carried out, and those that didn’t. Both were done while the was press stopped.

Typical activities that require the press to be stopped: unbolting the die, pulling it out of the press, bolting the die in place.

Typical activities that can be done while the press is running: finding the next die, and moving it next to the press, finding wrenches, and other tools, placing the new material next to the die.

Shingo called the first kind of activity “internal”, the second kind, “external”.

He found that typically, half the activites done while the press was stopped were external. As an industrial engineer, he realized that a bit of planning would yield a significant reduction in setup time. If the tasks that did not require the press to be stopped were done while the press was running, then the changeover would take half the time.

There are lots of reasons why internal and external elements are mixed – only one person is doing the setup, and there is no time to prepare, the next job isn’t chosen until the current run is finished, running the press and setting it up are separate jobs, and the setters wait until the run is finished, there is no pressure to set up quickly, the amount of time for setup is part of the schedule, so there is no need to rush, no one believes that setup can be reduced, everyone involved in the setup appear to be working as hard as they can, everyone hates setup, and want to stretch the run until the end of their shift.

The question that remains, once Shingo’s insight is understood, is how to put in place countermeasures to these reasons for long setups.