How time flies. It was another place and another time. I first wrote about the following stories over 16 years ago. Given the timeless nature of their reliability angles, I’m hoping my re-telling of them here will be of interest to newer members of the RAM community. So, here goes, starting with an account of a stopped clock.
We all realize that a stopped clock is exactly right twice each day. Reliable? Not in the least. But did you ever think about what “right” really means?
AS THE OLD CLOCK STORY WAS TOLD TO ME
During his walk to work each day, an old would would always swing by the town’s only jewelry store. There, he would stop and set his watch by the old clock at the front of the business. This went on for years. The shopkeeper would watch this routine with curiosity and respect for the old man’s consistency. Rain or shine, the old man’s daily ritual never changed.
One day, the shopkeeper finally stepped out of his doorway and asked the old man why he was regularly setting his watch there. This surprised the old man, but he was kind enough to answer what seemed to be an obvious question.
“You see,” he explained, “this old watch may not keep the best time in the world, but it’s the only one I have. And my job is the timekeeper at that old mill on the hill. I have to make sure the clocks up there are accurate. Then, every day at four o’clock I have to sound the whistle signaling shift-change time. So, I have to reset my watch each day to make sure I sound the whistle at the right time.”
The shopkeeper was puzzled. He told the old man, “As you can imagine, this old clock has served us well for many years. And it really doesn’t keep time that well any more. So each day at four o’clock, I reset it when I hear the mill whistle.”
The men then began laughing. And no wonder. They realized that, between themselves, they had been perpetuating their own erroneous time zone in that small mill town for years. In short, they had created a flawed standard that influenced time-keeping in the entire community around the mill.
This story should remind us each day of the many simple things we do that require thought and care. In many cases, our jobs and our organizations’ success depend on those things. What is our standard for doing the right things to take care of our plant and facility equipment? How do we make sure we’re doing the right things at the right times, the right way?
These questions bring me to a second story, one of a personal experience with an old machine in a modern manufacturing process.
AS I SAW THE OLD PLANT-EQUIPMENT STORY PLAY OUT
The machine we were working on was an old one, built in 1939 and refurbished in 1970. It was in remarkably good shape considering its age. It ran as part of a processing line, 24 hours a day, for 5 to 6 days each week. This machine was picked as a total-productive-maintenance (TPM) target since most of the product quality losses from the processing line could be traced to it. The data was complete, accurate, and reliable. But rarely was that data used to address maintenance problems the way we did with the pillars of TPM.
Underneath a 6-ft. long solid steel guard were two flat leather-faced belts. It takes two people to lift the guard off the machine. One of these belts was used to drive the intake drum, the other to drive a takeoff drum. Upon inspection of these belts they appeared to be worn beyond any usefulness. They showed signs of severe slipping. But, as the mechanics explained, according to plant standards, they were not to be replaced unless they were broken; “If they aren’t broke, we don’t replace them.” The preventive maintenance (PM) instructions said to “check the belts.” So, they checked them. They weren’t broke so they left them as found – worn and slipping.
Upon looking at small gears and roller chain on the other side of the machine drive system, we noticed a very heavy buildup of fibers. The plant’s PM instructions went on to say, “Clean all gears and chains. Oil the chain and sprockets, grease the gears.” That would seem normal, but it was the OPPOSITE of what the 1939 OEM manual recommended.
In fact, on the single page of the OEM manual that addressed lubrication, there was this warning note: “Do not grease or oil the gears and chains.” As the note explained, “There is extra clearance designed into these the gears, chain, and, sprockets to prevent a buildup of fibers. Grease and oil will attract fibers and cause the parts to bind and jam and the belts to slip. Slipping belts will cause uneven material thickness.”
So, what about belt slippage? Erratic feeding due to belt slippage was the single largest cause of product defects in the entire manufacturing process. What is the root cause of belt slippage? Not checking the right source for proper maintenance, e.g., the OEM manual; not using the right information to perform the right maintenance at the right time on a critical piece of equipment; assuming that a “common-sense approach to basic maintenance” applies across the board. Pick one.
After all, every mechanic in a plant at that time knew gears needed grease and chains needed oil. Why would we have thought our gears and chains were any different? (A Note of Warning to All: Read the OEM Manual!)
THE TAKEAWAY FROM THESE OLD STORIES
Let’s circle back to the questions in the second paragraph of this article. “Right” means doing what the equipment requires. “Right” means consulting accurate and reliable sources to determine the right things to do. “Right” means “right” without a doubt, e.g., reliance on facts not opinions. In the end, equipment reliability depends on all of us doing the right things, the right way, at the right time, every time.TRR
ABOUT THE AUTHOR
Bob Williamson is a long-time contributor to the people-side of the world-class-maintenance and manufacturing body of knowledge across dozens of industry types. His background in maintenance, machine and tool design, and teaching has positioned his work with over 500 companies and plants, facilities, and equipment-oriented organizations. Contact him directly at 512-800-6031 or [email protected].
Tags: reliability, availability, maintenance, RAM, skills training, workforce development, workforce issues
