Steps to shorter setups

We have seen that separating the internal and external elements of a setup, and carrying out the external elements while the value is still being created, is the first and usually largest part of reducing setup time.

The complete list of steps to minimizing setup time is:

1. Separate internal from external, and carry out external operations while value is still being created.
2. Carry out the internal operations as several simultaneous operations.
3. Convert internal operations to external operations.
4. Simplify and automate all remaining internal operations to speed them up.

Briefly, these steps are understood as follows.

Carry out internal operations as several simultaneous operations: This is often referred to as “parallel work”. The typical image is of the race car pit stop, where four tires are changed, fuel is topped up, the wing is adjusted, and so on, in just a few seconds. Anyone who has watched a car race will have seen how this is done – utilizing five, six, or more pit crew. By analyzing the tasks of the pit stop, and dividing the work into tasks that can be done simultaneously, the internal work is done in a fraction of the time it would take if only one task was done at a time.

Convert internal operations to external operations: Many internal tasks consist of replacing and assembling several parts of a machine, a file of information, a kit of some kind, and any other setup that has several components. Take the above example of the pit stop – a tire change consists of replacing a tire mounted on a rim. By mounting the tire on a rim prior to the pit stop, what would otherwise be an internal activity (putting the tire on the existing rim) has been converted to an external activity, at the expense of having an extra rim. Another example is the use of a kit of materials, tools, parts, etc., that eliminate searching and selecting. A large part of internal operations that is usually considered separately is measuring and adjustments, to assure that the value creating operation produces an output that meets specification. By standardization, these operations can be eliminated.

Simplify and automate all remaining internal operations to speed them up: Further setup reduction allows value creation to more closely match demand economically, but safety, repeatability, and ergonomics must not be sacrificed. This calls for simplification and automation of tasks such as fastening, moving, data entry, and communication. Special tools and programs, codes and signs, design for changeover, and other similar approaches are utilized to gain speed.

It is, of course, also necessary to apply some of these techniques and technologies to the external setup. With shorter setups, and shorter periods of value creation between setups, external operations must be carried out in less time. This means better organization, simplification, mistake proofing, and automation.

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.