Equipment World Digital Magazine
Issue link: http://read.dmtmag.com/i/662812
EquipmentWorld.com | April 2016 33 inspection for leaking cylinders, worn undercarriage parts, or anything out of the ordinary. These inspec- tions should correlate to scheduled PMs at specific intervals like miles, metered hours or tonnage. Priority 2. Complete within five days. Continuing on with the inspection, your operators should report any abnormalities they see, hear, smell or feel when the machine is working. These can include exces- sive vibration, a funny feel to the controls or drive- line, change in sounds, smells (such as unburned fuel or overheated engine oil) or visible smoke. Priority 1. This is when damage occurs. You've already run the machine or component to the point of failure, and work ceases. There is no choice left but to repair it. MAINTENANCE STRATEGIES On the inside of the Priorities shell on the P-F curve, you will see a series of acronyms that de- scribe the maintenance strategies associated with those particular time frames. These include: • PdM: Predictive Maintenance, sometimes referred to as Condition-Based Maintenance (CBM). These are processes that use known engineer- ing limits and technology to detect an alteration in equipment condition. Examples could include oil analysis, vibration analysis, infrared and ultrasonics, to name but a few. It can also include Performance Trending, which uses history to project when the failure will likely occur, so replacements or repairs can be scheduled before the failure. • PM: Preventive Maintenance. As time passes, you rely on preventive maintenance and visual inspection by maintenance personnel to detect changes in equipment condition. Although you may perform lube and filter changes and other adjust- ments, the key activity here is inspection at the pre- scribed intervals to ensure individual components remain in spec. • OC: Operator Care. As you get lower down the curve approaching the failure event, many changes are more easily detectable. Operators, if trained, can detect those changes before failure occurs by using their senses of touch, hearing, sight and smell. The objective is to use a mixture of physical inspections and technology to detect changes early and prevent failures from occurring. • EM: Emergency maintenance. These are re- pairs you must make immediately to prevent a com- ponent failure from cascading into a larger, systemic problem. PROACTIVE MAINTENANCE (ProM) The vertical column on the left of the chart is a list of practices and programs you should implement to prevent breakdowns. Going from the bottom up, they are: • OC: Operator Care. One of the easiest and least expensive ways to save on maintenance costs is to make sure your operators are trained to detect physi- cal signs of change in the machine. "A well trained operator can detect 70 to 75 percent of failures in Maintenance strategy Methodology Human body equivalent Proactive maintenance Redesign, mitigating countermeasures, correc- tion of failure root causes, i.e. contamination Cholesterol and blood pressure monitoring, lifestyle change Predictive maintenance Monitoring of vibration, heat, alignment, wear Detection of heart disease using EKG or stress tests Preventivemaintenance Periodic component replacement Annual physicals, medication Corrective maintenance Planned repairs and replacements By-pass or transplant surgery Operator care Inspection with human senses, routine lubrication, cleaning, adjusting, minor repairs Managed nutrition, exercise Breakdown maintenance Emergency repair Heart attack or stroke The human health analogy If you're unclear about the differences between proactive, predictive and preventive maintenance, the chart below shows the similarities between equipment maintenance strategies and human health strategies.