Equipment World Digital Magazine
Issue link: http://read.dmtmag.com/i/662812
EquipmentWorld.com | April 2016 31 I f you're finally at the point where you realize poor maintenance practices cost you money (and good main- tenance is well worth the money you invest in it), congratu- lations. You're on the right path. But a lot of people struggle to move beyond the basic premise of "preventive maintenance." For some, all PM entails is fluid and fil- ter changes. There's a lot more to it than that, including more cost savings and uptime, if you use the chart on the follow- ing pages as a basis for your strategies and actions moving for- ward. The P-F Curve origi- nated from research performed by United Airlines and the Department of Defense by engineers Stan Nolan and Howard Heap. Nolan and Heap discovered that the traditional approach (us- ing nothing but typical preventive maintenance) was a poor way to manage equipment. Instead, they applied a rigorous engineering process to identify ways to drive down costs, increase uptime and prioritize maintenance activities. If you Google "P-F Curve", you'll find a lot of variations on this chart. The one we show on the following page is an itera- tion refined by Preston Ingalls*, a maintenance consultant with decades of experience in heavy equipment maintenance and man- agement. At the bottom right of the chart, you see the "Failure" sign. While component failure sounds like something you would want to prevent, Ingalls stresses that some things are better left to fail. For example, the dome light in the cab of a truck. The part is inex- pensive and its failure does little to hurt productivity or efficacy. So therefore, the economically sen- sible thing to do is to wait until it burns out, and then stop by the auto parts store for a new bulb. "We're not trying to eliminate failures," Ingalls says. "We are trying to eliminate consequen- tial failures." What all these charts have in common is that they show how most failures can be detected in advance if effective inspections are conducted. They also illustrate the condition of components as they degrade and approach fail- ure. To help you understand how to decipher the chart, we'll break it down into three main elements: the P-F curve, its relationship to Maintenance Strategies, and vari- ous Proactive Maintenance sug- gestions. maintenance | by Tom Jackson | TJackson@randallreilly.com USING THE P-F CURVE TO IMPROVE YOUR EQUIPMENT MAINTENANCE AND MANAGEMENT *Preston Ingalls, President/CEO of TBR Strategies has led reliability improvement ef- forts across 30 countries for Royal Dutch Shell, Exxon, Occidental Petroleum, Hess, Mobil Chemical, Aera Energy, Toyota, and many other companies. He consults with construction industry fleets on equipment uptime and cost improvement (www.tbr-strategies.com). Rigorous inspections and analysis keeps little things from turning into big problems.