Executive Summary:
- Goal of TPM is to maximize Overall Equipment Efficiency (OEE) by achieving near-zero downtime while cutting maintenance expenses.
- Increase output and productivity without increasing the size of your welding fleet.
- TPM promotes a philosophy that says “we are all responsible for this machine.” Getting operators involved with monitoring equipment helps them work better with the maintenance team and improve uptime.
- One of the best ways to prevent welding equipment downtime is to select equipment that has been designed for, and hardened against, the stresses associated with welding environments.
Better Welding Maintenance Strategies Enhance Contractor Competitiveness
When looking to boost welding output, contractors and engineering firms historically added more welding equipment and hired more welders. With the chronic shortage of qualified operations and tighter budgets, these tactics are now options of last resort. Instead of hiring and spending capital, today’s leading-edge companies boost welding output by implementing a Total Productive Maintenance (TPM) program to increase competitiveness.
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| Beyond filter changes. The lean TPM concept goes for beyond the normal oil change, filter change and Productive Maintenance procedures.
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In some circles, TPM also means Total Process Management, Total Productive Manufacturing or even Teamwork between Production and Maintenance. Whatever the acronym stands for, the objectives of a cutting-edge TPM program are they same. TPM enables a company to:
- Increase output/productivity without increasing the size of its welding fleet
- Meet deadlines easier and avoid outsourcing welding
- Conserve capital or free it for other uses
- Increase profit margins (which in turn can enable pricing flexibility if necessary)
- Improve cross-functional teamwork and communication
- Empower associates to not just solve welding equipment problems, but also to eliminate the source of the problem
Three Types of Maintenance
Maintenance expert Ross Kennedy, president of the The Centre for TPM (www.ctpm.org.au), notes that there are three levels of maintenance: frontline care, technical maintenance and strategic maintenance.1
On an engine driven welding generator, frontline care would be changing the oil and filters at recommended intervals. Technical maintenance would be having the engine drive serviced by a mechanic to fix a problem. Strategic maintenance is about minimizing maintenance costs. This could be through such actions as selecting the simplest, most reliable welding machines possible or standardizing your fleet on the fewest models possible (where component commonality reduces parts inventory and service training costs).
According to Kennedy, too many companies focus on technical maintenance (a “fix it when it breaks” mentality) and do not emphasize frontline care and strategic maintenance. This means the most painful jobs, such as breakdowns, receive greater attention than small defects-yet rectifying and eliminating the source of small defects could save more money in the long run.
When feasible, operators should be responsible for day-to-day maintenance because no one knows a welder better than the person who uses it daily. The maintenance department should focus more on technical and strategic maintenance for the welder. TPM promotes a philosophy that says, “We are [all] responsible for this machine…and between us we will determine the best way to operate, maintain and support it.”2
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| Maximum uptime. Good maintenance practices allow welding equipment to survive in harsh environments.
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For success, management must form a cross-function team. This “removes the age-old philosophy that says, ‘I run it. You fix it,” Notes Dave Terres, corporate total-productive-maintenance (TPM) coordinator for Cold Spring Granite, one of the world’s largest producers of dimensional granite.3 Since adopting TPM, Cold Spring has lowered maintenance costs, downtime and major equipment failures. Better equipment uptime improved Cold Spring’s production to the point where, instead of investing heavily in new equipment to increase capacity, its existing equipment occasionally sits idle.
TPM does not ask operators to become mechanics, but it does ask them to be more involved in taking care of the equipment. For example, the operator could watch the hour meter and notify the maintenance department when the welder is due for preventive maintenance or an oil and filter change. TPM also asks that operators immediately alert maintenance to any problems or issues. For example, a loose wiring harness is a simple fix. But if it leads to a component failure and replacement parts aren’t in stock, then the welding machine may be down for several days.
True Downtime Cost
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| Lower operating cost. To boost overall equipment efficiency (OEE), select engine drives that cost less to maintain, are easier to service and are more reliable.
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The goal of a TPM program is to maximize Overall Equipment Efficiency (OEE) by achieving near zero downtime while cutting maintenance expenses.
However, while monitoring OEE per piece of equipment at least brings the focus on the equipment itself, it may not provide the true cost of downtime unless the cause is obvious. For this reason, resources such as the Business Industrial Network (www.DowntimeCentral.com) promote OEE if it is generated from True Downtime Cost (TDC) metrics. This involves tracking every cost associated with downtime.
For additional fleet asset advice, visit www.aemp.org, the home page of the Association of Equipment Management Professions. The AEMP’s mission is to advance professionals in the equipment maintenance and management industry.
Lean TPM
The Japanese “lean” philosophy now extends into maintenance. In fact, The Centre for TPM has modified the infamous Toyota Product System to create its own third-generation, or TPM, methodology. In the U.S., the concept of “Lean Maintenance™” is even trademarked by maintenance expert Howard C. Cooper. Cooper notes that the lean concept “goes far beyond the normal oil change, filter change [and] PM procedures.”
This is because there are three categories of downtime:
Downtime from operator error
Downtime from inadequate PM procedure or performance
Downtime from chronic wear and stress on system components from things such as heat, vibration, oxidation, corrosion, dirt build-up and voltage transients and current surges.
True Cost of Welding Equipment
One of the best ways to prevent welding equipment downtime is to select equipment that has been designed for-and hardened againstthe stresses associated with welding environments. If you haven’t ever done so, remove the cover of a Miller and put it side-by-side against a comparable model from another manufacturer. You’ll immediately notice the robustness of the Miller design: fewer components, components that are better protected against damage, better cooling airflow path and components that are easier and faster to service.
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Reliable cutting. Dan Chapman, owner of CMW Welding, only takes a single Spectrum plasma cutter with him, even when working on distant job sites, because he can rely on uninterrupted performance in any weather.
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“Any time you simplify a machine, it becomes more reliable and easier to operate,” says CRC-Evans Vice President Brian Laing, who helped select Miller inverters for mechanized welding on cross-country pipelines.
When it comes to selecting welding equipment that withstands harsh environments and operates in situations where downtime is costly, the “best” welding equipment is the equipment that is most reliable and prevents downtime.
“We put up a Holiday Inn down in Melbourne, Florida, in the middle of July and it was very hot-about 114 degrees F-and very humid. All of our equipment worked great through the conditions that we had,” says Dan Chapman, owner, CMW Welding. He especially notes the durability of the Spectrum plasma cutter, which ran without fail off the generator power of a Trailblazer® 302 gas engine drive.
Miller equipment also performs in cold weather, too. “The PRO 300 [diesel welding generator] worked year round and never caused any problems,” says Edward McNaughton, a Canadian welder with Nordcap Steel Docks. “We were amazed at the cold-weather starting. The people will give out before the machines do.”
Interestingly, equipment that is initially more expensive and perhaps considered over-sized for some jobs can make for a much smarter acquisition.
“A Big Blue® [diesel engine drive] costs half as much to maintain compared to smaller units,” notes Terry Gallant, equipment coordinator, Cianbro Corporation. “Its reliability is second to none. No other welding generator comes near to matching it for reliability and economical service. With regard to the XMT® [inverter], we compared four brands of welders. The durability on the XMT has been really good, and it beats everybody on user-friendliness.”
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| Better protection. One of the best ways to prevent maintenance-related downtime is to select equipment with fewer, more reliable and better-protected components. For example, Miller houses the control board for its PRO 300 and Big Blue engine drives in a water-tight Vault, shown here submerged-and still operating-in a fish tank.
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Unfortunately, reliability statistics don’t show up on spec sheets. This can make it hard for maintenance managers, operations managers and engineers to justify investing in welding equipment based on its reliability, especially when working with top management or purchasing agents without welding experience. As noted earlier, forming a cross-function team is one way to address this issue, as it would benefit those unfamiliar with welding to “walk a mile in a maintenance manager’s shoes.”
Another method of assessing reliability is to ask a welding distributor service technician which equipment offers the best reliability, which equipment is the easiest to service and which manufacturer offers the best support. Considering the true cost of welding equipment downtime, not asking these questions could be a costly mistake.
For recommendations on the welding equipment that offers the best reliability and can help you maximize overall welding equipment efficiency, contact your Miller representative. For information on Miller equipment, visit MillerWelds.com.
1Kenney, Ross. Outdated ideas a barrier to equipment uptime. August 3, 2006.
2Wilmott, Peter. McCarthy, Dennis. TPM: A Route To World-Class Performance. Oxford: Butterworth-Heinemann, 2001.
3 Stewart, Larry. “Maintenance Reduces Fleet Size.” Construction Equipment. September 1, 2003 http://www.constructionequipment.com.
4 Cooper, Howard C. Lean Maintenance within 30 days. August 3, 2006. <www.amemco.net