Mothers and Daughters
Copyright© 2017 by Lazlo Zalezac
Jim Samson, the on-site manager of the chocolate company, led Sherry and Harry on a tour of the chocolate factory. The tour started at the beginning of the production line, where fresh ingredients were stored in a large automated warehouse. As they walked, Jim talked about the process by which raw cocoa became a consumer chocolate bar.
Jim said, “This is a continuous production facility. That means that our product flows continuously through the factory, without pause. Raw ingredients come in, and finished product comes out the other end of the line. We time everything, so that product is continuously produced.
“The only time we shut down a production line is when something has broken or we are changing over to a different product. This particular line is used for five different chocolate products.
“Shutting down the production line is not a simple process. We have to shut everything down from beginning to end in the proper order. When a part in the middle of the production process breaks, we basically have to throw everything prior to that point, away. You can’t have chocolate just sitting in the cooking vats for too long. Everything after a break can continue to function until the last item has completed the process, but you have to turn off the equipment when they are about to run empty.
“Everything has to run correctly for the end result to meet our high quality standards. Between each major production machine, we take samples to assure that everything is functioning correctly. We measure everything, from the viscosity of the melted chocolate to the color of the product.
“Quality control is very important in our business. People buy our product expecting it to taste just like the last time they ate one. Everything has to be clean – very clean. Our facilities here are cleaner than any home kitchen. There’s nothing worse than discovering a clump of foreign material in your candy bar.”
Harry interrupted Jim, “What that means is that our machines can’t leak oil or grease. The high quality constraints, means that our machines have to perform millions of operations identically across all of them. We can’t allow any slop, in any part of the machine.”
Sherry said, “I can understand why.”
She had been impressed with almost every step of the tour. They had machines that boggled the mind. There were huge industrial mixers, machines that applied various coats of materials, refrigerators, and other things; with pipes or conveyor belts carrying product from place to place. Everything ran non-stop.
Jim said, “That’s right. On some of these machines we can’t afford even a thousandth of an inch off in alignment. You’ve never seen anything until you’ve watched candy bars start flying off a production line.”
“Does that happen often?” Sherry asked.
“No. It’s never happened here, but it has happened at another facility,” Jim answered.
He pointed around the facility and said, “Our production rates today are almost a thousand times faster than when this factory was built. For a purely mechanical process, that is an amazing achievement.”
“You can say that again,” Sherry said.
They stopped in front of a machine that was packaging the chocolate bars. Chocolate bars and wrapping material came in one side and wrapped chocolate bars came out the other. The speed at which it worked was so fast that the eye couldn’t make out all of the details.
Sherry carefully approached the machine on which she was going to place the sensors. There were a lot of moving parts and she didn’t want to get the lab coat she was wearing caught in the machine. She looked it over very thoroughly making note of every part that was moving. There were a lot of moving parts and she knew that she couldn’t see all of them. It was a lot bigger than the little lathe from which she had gathered her data for her dissertation. It was also loud. The whole area was loud.
She backed away from the machine, turned to Harry and said, “That’s a honking big assed machine!”
With a grin on his face, Harry replied, “I know.”
“I want one of them,” she said.
“What for?” Jim asked surprised by her statement.
“I want to take it apart,” she said licking her lips.
Harry laughed. He had not expected her to say something like that. He also appreciated the hungry expression on her face. She didn’t know it, but when he interviewed prospects for engineering positions that was the one statement that almost assured he would hire the candidate. His opinion of her went up ten-fold.
He said, “You can watch us put one together.”
“That would be cool,” Sherry said.
With real pride in his voice, Harry said, “That was the first machine I designed when I started working for my father. It can package four hundred pieces per minute. Right now, I’d say that’s running at around three hundred.”
Jim said, “You’re right on – it’s set for three hundred pieces per minute.”
“I’m quite proud of that machine.”
“You should be proud of it. It’s a marvelous machine,” Sherry said.
She leaned over and listened to the machine for a second. There was a little undercurrent of noise that didn’t sound right. It was a low frequency thrum that occasionally changed volume. Considering that the machine was operating in a steady state, there shouldn’t have been any volume changes.
“It doesn’t sound right,” she said with a wrinkled brow.
Very impressed with her observation, Harry said, “That low frequency vibration you hear will slowly get louder and louder as well as changing in frequency. After a bit, it will stop creating a complete seal on the merchandise. They’ll have to break down the machine and replace one of the bearings on a rocker arm soon.”
“I’m hoping that we’ll finish this run before then,” Jim said letting his concern show. “That’s why we aren’t running it full out at the moment.”
“Don’t the people running the machine notice the odd vibration?” Sherry asked looking over at Jim.
Rather than Jim answering, Harry said.”I’d be surprised if they did. You get used to hearing the machine, and don’t notice gradual changes in sound like that. They could have replaced the bearing the last time it was down for general maintenance and cleaning if someone had noticed it. Now they’ll probably have to halt production to fix it.”
“That’s a really impressive machine,” Sherry said.
Harry said, “It’s much more versatile than you might think. This same machine is used to package and seal all kinds of products. We have this particular line of packaging and sealing machines in factories that make everything from cup cakes to kitchen sponges.”
Upon hearing that, Sherry looked at the machine with a frown. She noticed that there were a dozen different places where adjustments could be made. She looked back at Harry and then back at the machine. His comment had just let her know that her job had just increased in difficulty a hundred-fold.
“What’s the matter?” Harry asked.
“You’ve got a lot of adjustments that can be made for this one machine. I imagine that the characteristic noises that it makes, will differ based on the setting,” Sherry said.
“That’s right,” Harry said.
His first reaction upon learning that a woman had developed the diagnostic software had not been entirely positive. He had imagined some dainty young thing that didn’t know anything about equipment or mechanics, but could write a computer program in a nice clean office. The only factor in favor of giving her a chance was that Alex Cage had recommended her program to him. Now that he had a chance to meet her, he was pleased to discover that she thought like a real engineer.
“That’s going to be a challenge,” Sherry said.
“Why?” Harry asked.
Jim leaned forward with concern. He wanted to hear what she had to say.
Sherry said, “Each setting may produce different sound profiles for normal operation. Those differences could mask abnormal sound profiles that could be produced while it is approaching failure under a different setting. I’ll have to make recordings under a variety of settings, just to establish some baseline readings.”
“I didn’t think of that,” Jim said.
Harry said, “I’ve been around these machines for years. The differences in sound aren’t that great.”
Sherry replied, “Yes, but, as you say, there are differences. That could be very important when it comes to diagnosing future failures of the equipment.
“Take this machine right here. If the timing between the candy bar, the wrapper, the sealer, and the cutter is off just a little bit, you’ll have labeling that is offset from the candy bar, cuts through the chocolate rather than the ends of the wrapper, or bad seals. However, you put a different product through here, then everything could be perfect.”
Jim said, “We do have to adjust the settings when we change from one chocolate product to another.”
Sherry said, “Exactly. My program has to work within tolerances that are just as tight, in much the same way as this entire factory does. It has to distinguish between a normal signal for one set of settings and a failure signal for another set of settings when the vibrational characteristics are almost identical.”
Harry said, “I can see where that would be a problem.”
“It’s a little tougher of a problem than I anticipated; but, so far, I haven’t seen anything that is a deal breaker,” Sherry said trying to sound a lot more confident than she felt.
She wondered if there weren’t too many degrees of freedom in the operation of the machine. Ten controls with even two different settings each could produce over a thousand different behaviors. In her opinion, that would be about the limit of what her program could handle. She couldn’t imagine the difficulties in trying to train the system for a thousand cases where it was functioning correctly along with the thousands of cases in which it was about to fail. It really could be a mess.
She listened to the machine in operation. She could hear that there were several different frequencies being generated. There was the high pitch of a rotating part. The rhythmic sound of the cutter. There was the reedy sound of the wrapper flowing through the machine. She could probably put in a filter that tracked each major source of vibration individually.