A Little Dab Will Do Ya

In 1991, I was offered a line supervisor position at Armstrong’s ceiling grid factory in Franklin Park Illinois. I had been working as a staff Industrial Engineer at Thomasville Furniture in Thomasville North Carolina, so the position would be my first operations supervisory role.

I spent my first few months at the plant learning everything I could about the manufacture of ceiling grid and the approach I would take to supervising my small crew of factory workers. The only way I knew to learn was to spend as much time as possible on the factory floor, observing, asking questions, and trying to help where I could.

The factory had eleven separate operating lines and each of them made a variety of products. Each line consisted of an unwind station for coils of steel, roll-formers that bent the coil of steel into the shape of the ceiling grid, and a punch press which stamped out the holes and end details for each piece of grid. Finally, there was a packaging station that assisted the operators as they put the finished pieces in a box.

The lines operated fairly well, with limited downtime, until it was time to change over from one product type to the next. If the shape of the grid was changing, rolls on the roll-former would be switched out. If the size or shape of the product were changing, dies in the press would need to be moved or switched out. The process of changing over was long and drawn out and we never started right up after the changeover. I wanted to know more about this, but typically the highest skilled employees did the changeover and didn’t want to be bothered by my questions.

An Observation In Need of a Solution

After a few months of observing things, I decided that I needed to help somehow. I really wasn’t sure what I could do to help. I decided I would first try to better understand press die setup, as it looked more straight-forward than roll former setup. Spending many hours observing what was happening, I noticed that once the dies were placed in the proper location, they were then tightened using bolts. Then, a bar of grid would be stamped and checked for proper placement of holes, end details, and overall length. Tolerances were tight, so the dies would have to be placed accurately.

Every time this was done, the measurements required that the setup operator make adjustments to the location of the dies. I didn’t understand why this was. Why couldn’t he just find the optimal position, tighten the dies, and be ready to run on the first try? He told me that the dies always moved a bit when tightened and he had to tap them to their final position with a mallet. If things went well, he could do this on one additional attempt. If things went poorly, it could take many attempts which added up to many hours of downtime. I thought to myself, “There must be a way to get the dies set properly on the first try.” I didn’t know what to do. Luckily for me, I was about to take a trip that would change the way I thought about this problem.

I was asked to travel to the new headquarters of our joint venture with Worthington Steel in Malvern Pennsylvania. I like to read bit on airplanes so I looked at the bookshelf in the supervisor’s office and saw a book called, “A Revolution in Manufacturing: The SMED System,” written by Shigeo Shingo. I asked the other supervisor if he had read it and if I could borrow it. He told me that Armstrong bought the book for all of their manufacturing sites in the late 1980’s, but he had never read it. He told me I could take it and keep it if I wanted. So, I took this book with me on the airplane and started reading it.

New Way of Thinking Inspired by Socks

It was like a whole new world had opened up to me. Shigeo Shingo developed a changeover reduction process that is used by companies the world over and even is used during pit-stops at auto races. This was just what I needed. But, where to begin? A story in the book about golf told me what to try first. In the story, Mr. Shingo talks about playing golf and getting blisters on his feet at the end of the day. He loved golf, but didn’t love the blisters that came as a result and decided he must reason out how to eliminate them. He used his problem-solving skills and figured out that the blisters came from the rubbing of his socks on his feet when he was swinging the golf clubs. Why were the socks rubbing on his feet? Because there was less friction between the socks and his sweaty feet than there was between the socks and his shoes, which he had put on quite tightly. How would he resolve this? He figured out that by adding another pair of socks on his feet, he could keep the least friction between the two socks and therefore they would rub against each other, rather than rubbing on his feet. Problem solved; blisters eliminated!

So how does this apply to changeover reduction, you may ask? Now that he saw how reducing friction was beneficial, he decided to apply the same idea to press die setup. He also had a problem with dies moving once they were tightened down. He originally had a bolt and one washer that he used to tighten down dies on a smooth press surface. He noticed that the die would move on the smooth press surface when the bolt was tightened securely. Much like the socks, he decided to add an extra washer to the bolt and put a dab of oil between the two washers, guaranteeing that they would have the least friction of any component in the setup. He tried his idea out and it worked. And now, I had something I could try back at the plant when I returned.

Results Even Skeptics Could Not Ignore

When I got back to my plant, I was excited to share what I had learned with my setup operators. I explained what I had read and they were not impressed. “How do sweaty socks help improve changeover time?” they asked. I said I thought we should try an experiment to see if what I read really did work. One of the operators grudgingly agreed to give it a try. I wanted to make sure that we had real data for our experiment, so I asked him to set up a die in position as he normally would. In this case, we set up dial indicators on two corners of the die. They would be used to show us how much the die moved when tightened to the press. We zeroed out the dial indicators just before he made the final tightening of the bolts on the die. One corner mover .007” and the other moved 010”. That might not seem like a lot of movement, but it is more than we could tolerate and would require him to move the die with a mallet, just as he always had to do.

Now it was time to try the new way. We added a washer to each bolt on the die and put a dab of oil between the two washers on each bolt. We zeroed out the dial indicators just before making the final tightening of the bolts on each die. To our amazement, at the final tightening of each bolt, the washers moved, but the readouts on the dial indicators both read 0! There was no movement of the die. “Let me try that again,” he said, and he did. Once again, there was zero movement of the die. This was a breakthrough. Now the other setup operators wanted to try it for themselves. They couldn’t believe it as one by one each of them saw the dial indicators stay at zero, no matter how hard they tightened the bolts on the dies.

We immediately added washers and oil to the dies waiting to be used on the other lines. Then, we modified the other dies on the production lines after we took them out of the presses following production runs. From then on, every die that was set up in our presses maintained its location, saving valuable time, effort, and reducing frustration. I like to think that I would have figured this out on my own, but I realize that we all get set in our ways and sometimes need a story or two to change our thinking. I don’t play golf, but I now have much greater respect for the game and what can be learned from it.