When LucasVarity's* 50 millionth anti-lock brake system (ABS) unit rolled off the line earlier this year at its Fowlerville, MI, facility, it was a shining moment for the company. "No other company in the world has achieved this milestone," stated LucasVarity Automotive president John Plant, "and each of our colleagues throughout LucasVarity Automotive shares in the triumph."
But as all the fuss was made over that finished ABS unit in the assembly area, 11 Makino manufacturing cells stood idle on the other side of the plant. You might imagine that they enjoyed their brief respite from machining the aluminum valve bodies that they'd been producing since the plant opened in 1994. If only we could have heard what the machines might have said during this aberrant interruption marking their five-year anniversary...
Okay, so machines can't talk—but their overseers can. Dennis Boyer, director of manufacturing ABS, and Thomas F. Sliwa, Fowlerville plant manager, have plenty to say about their experiences with the cellular manufacturing system. Fortunately for you, they were nice enough to share.
Boyer: "We started installing the first cell in January and by the end of June, we had the first six cells installed and all qualified."
Sliwa: "Now we've got installation down to about seven weeks."
On Ramping Up...
Boyer: "We bought six cells, then we bought three more, then we bought one more, then we bought one more. If we had done it in a more traditional approach, we would have bought one big chunk, then a second big chunk. That second big chunk would have been under-utilized for two years."
"Volume and capacity are very incremental [with a cellular system]. We have increments of capacity that are 150,000 to 200,000. If you go to buy traditional equipment, you have to buy increments of a million at a time."
Boyer: "If our engineers can figure out how to take 10 seconds out of a cut or reduce the index time by two seconds, we have the ability to make continuous improvement. Every improvement that they can make to take any cycle time out gets us more pieces. Back with a traditional approach, if you're not working on the slowest station on the line, you're not going to get any more pieces."
On Productivity and Cost...
Boyer: "I think a lot of cost estimating tends to be too conservative. We were hoping to get production rates of 85% out of our manufacturing cells. We estimated traditional manufacturing approaches at 70%. The difference is that we're getting 10% better production rates and, typically, you get 10% worse [than the estimate]."
Sliwa: "I'm going to throw it out there—it's not uncommon to run at 97.5%"
Boyer: "I had the misconception that you paid a big premium for the cellular approach. When you look at gross capacity, you do pay a premium. When you look at net capacity—what you're really able to get—it's not a premium. The reason is that traditional transfer lines run at about 60%. Our cells are running ninety-something. There's the difference."
Sliwa: "I don't think you can get any better. It's unbelievable the way the equipment runs. For the most part, the 66 machines out there, on most days other than when you're pulling them down for PM, they're running."
Boyer: "We came on line making more pieces per hour than we thought we were going to and we've continued—every day, every month, every year—to figure out how to get more pieces per hour off these cells. The reliability, the up-time and utilization are very high compared to traditional machine approaches."
Sliwa: "The first cells are five years old and they're still running just as reliably as the day we put them in. To me, they're definitely 8-10 year machines. We keep after the recommended maintenance schedule and I think it's really paid off."
Boyer: "We're using more polycarbonate diamonds [PCD] today than we originally did, because we were a little bit leery of the cost and concerned that they would break. In a traditional system, you get tool breakage because of mis-indexes and mislocations of parts. These things are not really the fault of the tool, but the tool is the weakest link. Once we saw that we weren't going to wipe out the tooling, it made us more comfortable with using a more expensive tool like PCD. The accuracy of the electronics of the CNC controller is very good. I don't think you'd get as good of finish-tool life on any other type of machine."
Sliwa: "Our tool life was really respectable when we started out and now it's even better. Our tooling cost per unit is extremely economical; it's very low."
Boyer: "If a machining cell ran 180,000 pieces a year, for example, and there are six machines in that cell, that means that each machine runs 30,000 pieces a year. A PCD insert will last for 100,000 pieces. So we've seen cells help reduce variability, as we're not changing tools all the time."
On Lean Manufacturing...
Sliwa: "If you look at finished goods, I only have about a day and a quarter in front of the assembly plant. The way I look at it, today we're making what we're shipping tomorrow."
Boyer: "In a traditional machining approach, you've got to have lots of raw material ahead of the line so that if they do take off you can keep them fed. You've got to keep enough of a buffer between machining and assembly so that when machining goes down you don't have to shut down assembly."
The bottom line is that these guys are extremely happy with their system. After five years, they feel like they're still ahead of the game where state of the art technology is concerned. We can only hope that when their 10th anniversary rolls around, the guys at TRW (the recent purchaser of LucasVarity) stop the line for another moment of reflection. After all, 10 years is the "Aluminum" Anniversary.