Leaning toward multitasking

Jan. 27, 2006
Shops find that cell-manufacturing rules don't apply to multitasking machines.

Kim Parrish (center) and the guys at Advanced Machining & Fabrication say their Mazak Integrex 100Y multitasking machine has let them take on new jobs.

Advanced Machining & Fabrication now produces complex parts for the aircraft and oil industries with multitasking machines.

With two Mazak e-650H multitasking machines, George Smith (left) and Rick Jones of Cooper Cameron Valves have slashed many part cycle times in half.

Multitasking machines improve machining valve-body castings at Cooper Cameron Valves and will eventually allow the shop to make them from solid bar stock.

The McKissick Division produces its trunnion parts on multitasking machines.

Kim Parrish operated the shop floor at Advanced Machining & Fabrication Inc. in Owasso, Okla., (www.advcosinc.com) for years using leanmanufacturing principles that say existing equipment should be arranged in manufacturing cells and one operator should run several machines. However, when business fluctuated, Parrish realized that survival hinged on investing in the latest manufacturing technology, and he brought in a multitasking machine. He soon learned what many other shops in similar situations have learned: Reaping the benefits of multitasking machines in a lean environment requires an entirely different way of thinking than cell manufacturing.

For example, when quoting a job in a cell manufacturing situation, Parrish has had to determine the operations that are needed and how many times parts move from one machine to another. Then, he factors in the extra time and labor for those part transfers and for multiple setups. With multitasking machines, part transfers and multiple setups are not required because the machines complete parts in one setup and in minimal amounts of time and with minimal labor.

Multitasking machines let Advanced Machining & Fabrication bid on jobs it would not have been able to in the past. "We no longer turn down jobs involving several time-consuming operations," says Parrish. "In fact, we offer competitive quotes and still make money on such jobs because the machines reduce the amount of required labor by 50 percent in most instances." As a result, Advanced Machining & Fabrication has had to also change how it gages productivity.

"We used to do cost accounting to the point of logging every labor hour and then evaluating the results upon job completion," explains Parrish. "We spent more time on this than focusing on productivity improvements."

Since adding the multitasking equipment, the shop benchmarks gains in productivity according to cycle times. It still bases quotes on a standard shop rate, but the labor portion is reduced.

Like Parrish, George Smith, a manufacturing engineer at the Cooper Cameron Valves division of Cooper Cameron Corp. (www.coopercameron.com/cgi-bin/ccvalve/home.cfm) in Oklahoma City, also has had to rethink job strategies since adding multitasking machines. For Smith, the biggest change was part volumes.

When Smith's shop relied on cellular manufacturing, it had to run large quantities of parts to meet productivity goals. Running high volumes compensated for the long setup and part-handling times associated with the manufacturing cells, according to Smith.

Multitasking machines make lowvolume work practical because there is less fixturing, equipment and labor involved, and they run parts faster than the manufacturing cells. "Instead of having to always think 'over 30 or 40-part jobs,' I can take on more of the onesytwosy-type work," says Smith.

Cooper Cameron Valves gages its productivity by the volume of parts its multitasking machines put out per day. It also compares the multitasking machines' cycle times to those of the shop's previously used machines.

The shop's two Mazak e-650H multitasking machines cut cycle times almost in half, Smith says, allowing Cooper Cameron Valves to bring work that was outsourced back home. For instance, it now manufactures 20 percent of its highperformance butterfly and ball valves in-house that were purchased previously from China, and it does so at a lower cost.

Shops such as Cooper Cameron Valves and Advanced Machining & Fabrication that use multitasking machines also must put more thought into determining the type of raw stock they use for particular jobs. They are no longer locked into using square or rectangular stock just because a part involves a lot of milling, or round stock because the part requires turning operations.

"You have to think outside the box with multitasking machines," says Parrish. "We were having difficulty locating rectangular-shaped bar material for some aircraft parts, but there was plenty of round stock available. So, knowing we had multitasking capability, we were able to run the job (with) round stock."

For another part made of the nickel-chromium-titanium superalloy A286, Parrish says engineers initially specified rectangular stock, but the shop used round stock on its Integrex multitasking machine, saving a huge amount of time in machining. For example, one milling operation needed to make the part from rectangular stock would have taken 20 minutes. The Integrex completed the part from round stock in about 7 minutes.

In addition, Parrish says the shop does not have to prep raw material for the Integrex as it has to do for the shop's milling machines. This also lets Advanced Machining & Fabrication add a barpuller to the Integrex, automating its operations.

At Cooper Cameron Valves, multitasking machines provide the option of machining parts completely from solid billets instead of castings or forgings. Smith says this drastically reduces lead times and increases flexibility.

Most shops agree that flexibility is a key benefit of multitasking machines in lean-manufacturing environments. Such flexibility not only allows these shops to jump from job to job, but also from industry to industry.

"We are a job shop, so we need machines versatile enough to handle our work for the aircraft, oil and gas industries," says Parrish. He adds that these jobs can involve machining any materials from acrylics and Teflon to 718 Inconel and Monel R400 and K500 to superalloys, and the Mazak machine cuts it all.

Multitasking machines also improve part accuracy. Not having to handle parts between operations eliminates the risk of stacked tolerances, reduces scrap rates and eliminates having to deal with fixturing.

While running a series of Inconel parts on multiple machines, for instance, Advanced Machining & Fabrication experienced a 30-percent scrap rate trying to hold 0.001-in. concentricity. Cutting the parts on its Integrex 100Y multitasking machine from Mazak slashed the rate to 1 percent.

Like Advanced Machining & Fabrication, the McKissick Division of The Crosby Group Inc. in Tulsa, Okla., (www.thecrosbygroup.com) meets demanding tolerances with multitasking equipment. "Parts may look the same, but quality requirements are constantly changing," says General Manager Joe Gardner.

The shop manufactures blocks, tackles, hooks, sheaves and other components for cranes and tow trucks. It has improved part quality with its Mazak multitasking machines and simultaneously boosted volumes with the same number of people. For example, trunnion parts that took four to five weeks to produce on six machines now are done in an hour and a half on one Mazak machine.

"In good times, customers want parts fast, meaning shops need to shorten cycle times," says Cooper's Smith, "but in a downturn, they want the same parts at lower prices, forcing us to streamline operations and cut costs. Multitasking machines give us the versatility to succeed in either of these scenarios."

The shop also eliminated 23 pieces of equipment — mostly lathes and machining centers — since it installed its three multitasking machines. And the machines free employees for other, more important operations.