"Not only don't we use them, just found out we sold them a year ago," says Ralph.
"Everybody down in that department knows those machines aren't there anymore, so it's never been a problem," says Bob.
So it goes. We're trying to calculate demand for every re- source, every piece of equipment, in the plant. Jonah had said a bottleneck is any resource which is equal to or less than the mar-
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ket demand placed on it. To find out if we've got one then, we concluded we first would have to know the total market demand for products coming out of this plant. And, second, we would have to find out how much time each resource has to contribute toward filling the demand. If the number of available hours for production (discounting maintenance time for machines, lunch and breaks for people, and so on) for the resource is equal to or less than the hours demanded, then we know we've found our Herbie.
Getting a fix on the total market demand is a matter of pull- ing together data which we have on hand anyway-the existing backlog of customer orders, and the forecast for new product and spare parts. It's the complete product mix for the entire plant, including what we "sell" to other plants and divisions in the com- pany.
Having done that, we're now in the process of calculating the hours each "work center" has to contribute. We're defining a work center as any group of the same resources. Ten welders with the same skills constitute a work center. Four identical machines constitute another. The four machinists who set up and run the machines are still another, and so on. Dividing the total of work center hours needed, by the number of resources in it, gives us the relative effort per resource, a standard we can use for com- parison.
Yesterday, for instance, we found the demand for injection molding machines is about 260 hours a month for all the injec- tion molded parts that they have to process. The available time for those machines is about 280 hours per month, per resource. So that means we still have reserve capacity on those machines.
But the more we get into this, the more we're finding that the accuracy of our data is less than perfect. We're coming up with bills of material that don't match the routings, routings that don't have the current run-times-or the correct machines, as we just found out-and so on.
"The problem is, we've been under the gun so much that a lot of the updating has just fallen by the wayside," says Stacey.
"Hell, with engineering changes, shifting labor around, and all that happening all the time, it's just plain tough to keep up with it no matter what," says Bob.
Ralph shakes his head. "To double-check and update every piece of data relevant to this plant could take months!"
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"Or years," mumbles Bob.
I sit down and close my eyes for a second. When I open my eyes, they're all looking at me.
"Obviously, we're not g ing to have time for that," I say. "We've only got ten weeks now to make something happen be- fore Peach blows the whistle. I know we're on the right track, but we're still just limping along here. We've got to accept the fact we're not going to have perfect data to work with."
Ralph says, "Then I have to remind you of the old data processing aphorism: Garbage in, garbage out."
"Wait a minute," I say. "Maybe we're being a little too methodical. Searching a data base isn't the only way to find an- swers. Can't we come up with some other faster way to isolate the bottleneck-or at least identify the candidates? When I think back to the model of the boys on the hike, it was obvious who the slower kids were on the trail. Doesn't anybody have any hunches where the Herbie might be in the plant?"
"But we don't even know if we've got one yet," says Stacey.
Bob has his hands on his hips. His mouth is half open as if he might say something. Finally, he does.
"Hell, I've been at this plant for more than twenty years. After that much time, I know where the problems usually seem to start," he says. "I think I could put together a list of areas where we might be short on capacity; at least that would narrow the focus for us. It might save some time."
Stacey turns to him. "You know, you just gave me an idea. If we talk to the expediters. They could probably tell us which parts they're missing most of the time, and in which departments they usually go to look for'them."
"What good is that going to do?" asks Ralph.
"The parts most frequently in short supply are probably the ones that would pass through a bottleneck," she says. "And the department where the expeditors go to look for them is probably where we'll find our Herbie."
I sit up in my seat. "Yeah, that makes a lot of sense."
I stand up and start to pace.
"And I'll tell you something 7 just thought of," I say. "Out on the trail, you could tell the slower kids by the gaps in the line. The slower the kid, the greater the distance between him and the kid in front of him. In terms of the analogy, those gaps were inventory."
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Bob, Ralph, and Stacey stare at me.
"Don't you see?" I ask them. "If we've got a Herbie, it's probably going to have a huge pile of work-in-process sitting in front of it."
"Yeah, but we got huge piles all over the place out there," says Bob.
"Then we find the biggest one," I say.
"Right! That's got to be another sure sign," says Stacey.
I turn and ask, "What do you think, Ralph?"
"Well, it all sounds worth a try," says Ralph. "Once you've narrowed the field to maybe three of four work centers, it won't take long for us to check your findings against the historical data just to be sure."
Bob looks at Ralph and says in a kidding voice, "Yeah, well, we've all seen how good that is."
But Ralph doesn't take it in a kidding way. He looks embar- rassed.
"Hey, I can only work with what I've got," he says. "What do you want me to do?"
"Okay, the important thing is that we have new methods to try," I say. "Let's not waste time pinning the blame on bad data. Let's get to work."
Fueled by the energy of new ideas, we go to work, and the search goes quickly... so quickly, in fact, that what we discover makes me feel as though we've run ourselves straight into a wall.
"This is it. Hello, Herbie," says Bob.
In front of us is the NCX-10.
"Are you sure this is a bottleneck?" I ask.
"There's some of the proof," he says as he points to the stacks of work-in-process inventory nearby-weeks of backlog ac- cording to the report Ralph and Stacey put together and which we reviewed about an hour ago.
"We talked to the expeditors," says Bob. "They say we're always waiting for parts from this machine. Supervisors say the same. And the guy who runs this area got himself a set of ear- plugs to keep him from going deaf from all the bitching he gets from everyone."
"But this is supposed to be one of our most efficient pieces of equipment," I say.
"It is," says Bob. "It's the lowest-cost, highest-rate means we have of producing these particular parts."
"So why is this a bottleneck?"
"This is the only one like it we've got," he says.
"Yes, I know that," I say, and I stare at him until he explains.
"See, this machine here is only about two years old. Before we installed it, we used other machines to do what it does. But this machine can do all the operations that used to take three different machines," says Bob.
He tells me about how they used to process these parts using the three separate types of machines. In one typical instance, the process times per part were something like two minutes on the first machine, eight minutes on the second, and four minutes on the third-a grand total of fourteen minutes per part. But the new NCX-10 machine can do all three processes in ten minutes per part.