Quick changeovers are a must for an operation that runs machinery and intends to switch to lean manufacturing.
David Collins explains how a Chinese factory can change from one part to the next in an efficient manner:
- Simplified tooling
- Good planning of production and material delivery
- Good maintenance
There was a time in the auto industry when, if they had to change a die out to make the hood of a car or a door of a car or something like that, it took over 16 hours (to change the die). Today good car manufacturers change a die in less than 8 minutes. Now that kind of changeover took some good thinking, some good processes and good ways to do it.
One of the big problems I find here in China is when the factory has a high product mix, they constantly complain that they can’t change over very fast, they can’t make the production changes occur, and so what they end up doing is having sometimes hours of lying downtime because changeover changes are very hard to do. Well, I’m here to tell you that it’s not. With good planning, setups right, you too can go from that 16-hour to 8-minute changeover time and you too can change over your products so that it’s coming.
Using tooling techniques that make it easy for your tooling to be changed and simplified – maybe even the tooling change can be done by the operator himself as part of the changeover process because you’ve simplified in such a way, and your engineers did such a nice job doing the simplification, that they can change over. I’ve seen that many times.
Also, you can know through good production planning what’s going to be coming down the line soon. And so by knowing that your material delivery people can start setting up the materials necessary for the next line run as well as your engineers or other people (supervisors…) getting ready for that next run and the preparation happens and is the last piece of one run goes down the line. Maybe you have two or three job stations of emptiness and then the next piece of the new one can run because you’re prepared and you’re ready to go. You’re ready to get on the line right away.
In a computer factory I worked at, we used to take change over for two and a half hours every time we were going to make a different computer. And this is a factory I actually managed. We got that down to less than 15 minutes of changeover time. Think about what that did for my productivity, think about what it did for reduction of overtime and other problems we would have. Think what it did for getting the computers out the way my customer needed them on time.
So, again, there’s very good techniques and let’s review them one more time. Simplify tooling so that the tooling can be changed over quickly, really strong production planning, good maintenance so that machines can be changed over quickly, and then planning of the materials so that materials are on the line when they need to be delivered so that the production people can have those materials as they need them. Then your production people don’t stand up and walk around, they continue to work and that’s exactly what they’re supposed to do.