Install Maintenance Into Your 24/7 Schedule
Constant uptime is a good way to ensure excellent customer service, but it’s impossible without vigilant equipment maintenance. Here’s advice for newcomers to the always-open world.
By Tom Andel, chief editor
Working 24/7 is old hat for the process industries, but for discrete manufacturing, it’s a growing trend. As such, there are also painful lessons to learn along the way — little details that are easily overlooked in the rush to meet customer service requirements. Of course, when you rush, material handling equipment is stressed and eventually things break. That’s why maintenance is such an important element in the transition to continuous operation. It’s also one of the most overlooked.
“One of the big issues when you expand to 24/7 is you lose the weekend flexibility for maintenance,” says Bill Sirois, senior vice president and chief operating officer, Circadian Technologies Inc., a consulting firm specializing in management of the 24/7 workforce. “You’ve always had access to the equipment on the weekends. Now you have to redistribute how you’ll handle that maintenance.”
And suddenly you have another conflicting factor. The maintenance employees are usually the most senior people who’ve bid into the higher-paying jobs that maintenance offers. They are accustomed to working day shifts. Most companies retain the core of their maintenance function on the day shift and assign a skeleton crew to tackle the fringes of the full 24/7 schedule — in case of emergencies.
But those contingencies might not be sufficient safeguards. At Cooper Tire’s Texarkana, Arkansas, plant, conveyors run at high speeds. If one goes down, it must be fixed within minutes. When this plant switched to 24/7 two years ago, it added 500 people to the payroll. It also added equipment.
“If you expect to go 24/7, you must have enough extra equipment around to do decent maintenance on your main line equipment,” says Bob Nelson, vice president operations at this Cooper plant. “Our lift truck fleet grew by 15 percent. We have staged component assembles for our conveyors that we can swap out in a matter of minutes. There are no weekends for catch-up in a 24/7 operation, so you have to learn to do a whole lot more planning. If you’re as capital intensive as we are in the tire business, you won’t be competitive in the world if you allow factories to sit idle 35 percent of the time.”
Indeed, Tom Henderson, maintenance manager at this Cooper plant, says going 24/7 can increase production capability and profit margin by 40 percent — as long as you minimize in-process inventory and synchronize processes.
Retrofitting to 24/7
Integrated material handling is a lot easier to achieve if it’s accomplished in one project and installed in a custom-built facility. But that wasn’t the case for this Cooper plant. It was more than 30 years old when the 24/7 switchover was made. Material handling systems — primarily conveyor — had been upgraded gradually over the last 10 years. That makes maintenance an act of supreme timing and agility.
For example, the finishing area has conveyor systems over which every tire in the plant must travel. If you take out a 20-foot section of this conveyor for maintenance, you also have to lock out the conveyor before and after it. This gives you 300 feet of disabled conveyor. In a facility that was originally designed for five-day weeks, that can be a problem.
“We are putting in conveyors that will allow us to bypass these sections, but it’s a very slow process,” says Henderson. “You have to decide how and where you’ll put this conveyor, and whether it will give you the same functionality as the conveyor you’re bypassing. In most cases it will not. You may have a first-line conveyor with diverters and drop gates and all kinds of high-tech functionality built in. A bypass conveyor is low-cost and designed for infrequent use. You replace that lost functionality with people power.”
That means a person on a conveyor catwalk hand-diverting a tire to a particular machine. Worst case, it may mean letting the product circle until you’re through with your maintenance work.
“Integrating a bypass system with your existing equipment is a complex engineering process,” Henderson says.
If your facility was originally designed for a five-day work week, converting it for seven-day operation requires considerable work. After living through it himself, Tom Henderson offers the following advice:
• Remember your utilities. A 5-day-a-week operation can deal with a minor gasket leak by taking the whole steam line down over the weekend. A 24/7 operation must be gridded in zones so you can isolate any problem.
• Go modular. Even if it’s more cost-effective up front to put in a 300-foot stretch of conveyor, consider installing three 100-foot sections. Again, isolating the problem makes this more cost-effective in the long run. Cooper stocks complete head roll assemblies for its conveyors, with pre-installed bearings and integrated side frames.
• Stay current on technology advances. Henderson is looking at installing automatic belt-tracking devices to keep conveyors running.
• Don’t panic if costs go up initially. Even though 24/7 operation can give you 40 percent more production capacity, you’ll also have an equivalent increase in maintenance costs due to the initial investment in on-hand replacement parts and maintenance material. Eventually those costs trend downward, assures Henderson.
• Work with nearby 24/7 equipment vendors when possible. That can cut down on your cost in central stores.
• Increase your preventive maintenance frequency. An extra 36 hours of duty per week stresses lift truck engines and components. Cooper went from doing PMs every 30 days to performing them every 24.
• Establish good communication between maintenance and production. This can help in synchronizing schedules and finding opportunities when equipment can be taken down.
• Use a computerized maintenance system that presents an accurate spare parts list. This helps maintenance keep PM downtime to a predictable minimum.
• Keep on training. Cooper does almost all of its own maintenance, except for lift truck engine rebuilds. “Those engines never cool down,” says Henderson, “and your oil and fluid levels have to be maintained. Training is critical because if an operator lets one shift go by without checking fluid levels, you can do tremendous damage.”
Step back and regroup
Nordenia USA took a different tack with lift truck maintenance — and with 24/7, for that matter. It doesn’t do either of them.
Nordenia was 24/7 until last March. Jay Martin, manager of production planning and logistics, says his company moved to a five-day schedule because of the flagging economy. His experience teaches an important lesson about the effects of 24/7 on the payroll.
“One of the biggest challenges for workers was they had built their lifestyles around overtime pay, and we cut all that out,” he says. “The 12-hour shifts we were working created a 48-hour week one week and a 36-hour week the next week. They averaged about 44 hours. That’s 10 percent overtime built in. When we cut down to a five-day schedule, we cut all the overtime out.”
Nordenia manufactures products for the flexible packaging industry. The equipment it maintains includes blown-film extruders, printing presses and bag-making equipment. Customers like Tyson foods and Procter & Gamble are also wrestling with the down economy, but they still maintain high expectations of their suppliers. That’s why Nordenia is working with Circadian Technologies on a plan to return to the 24/7 world.
“That’s the way we want to run our business,” says Martin. “It requires capital-intensive equipment, so the best way to make money in this business is to run that equipment all the time. Our strategy is to refill our capacity closer to 100 percent.”
Part of that planning is determining the best 24/7 shift arrangement for Nordenia’s employees. It originally had two maintenance people on each of its four crews. They’ve since reduced that to one per crew on a three-shift schedule.
Five-thousand-pound-capacity lift trucks play the major material handling role at Nordenia. They routinely handle tons of resin packaged in gaylord boxes, as well as heavy rolls of film. Twenty-four Nissan lift trucks comprise its fleet. Most are propane-powered, but a few electrics are dedicated to handling inks that have explosive potential.
Nordenia relies on its local Nissan dealer, Missouri Industrial Equipment, to maintain the fleet. It proved to be a more cost-effective alternative for them. “It lowered our maintenance staff and kept them focused on production equipment,” Martin explains. “This was well received by the logistics group as well as production. Part of the maintenance contract calls for them to respond within two or three hours, and they’ve done that. We challenged MIE to take ownership of the fleet, to keep us well within OSHA specs and to keep our run times as high as possible. They spend half a day or more once a week on site. Breakdowns have gone away.”
Martin adds that if his fleet were three or four times larger, it might make sense to have staff dedicated to lift truck maintenance. But if you throw conveyors into the mix, he’d still recommend going third-party for the lift trucks.
“Your staff will probably be consumed with conveyor breakdowns and PMs on bearings,” he concludes.
If you’re contemplating expanding to continuous production, Circadian’s Bill Sirois recommends that you take the time to think it through and plan it out before involving employees. It’s a very people-sensitive decision because you’re going to disrupt lives. So ask yourself:
• Do you have sufficient business to justify 24/7?
• What effect will this have on support operations like maintenance and material handling?
• Can your organization handle 24/7 as presently structured?
• If you’ll be pushing 40 percent more material through your operations, do you have the warehouse space to handle it?
• Are you prepared to present and sell the business case for going 24/7 to the workers?
Cooper Tire did the self-examination and decided they were ready. Nordenia stepped away from 24/7, but is preparing to go back.
Cooper’s Tom Henderson concludes: “If you work for a company that wants to increase productivity without a large capital investment, 24/7 is the way to go. It’s fraught with a tremendous amount of difficulty, but it gives you more control of product flow, and you can better meet customer demand.” MHM