Machinery Lubrication magazine published by Noria Corporation
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As I see It 2 | May - June 2014 | www.machinerylubrication.com For most plants, condition moni- toring consists of multiple technologies that are cobbled together in an attempt to enhance machine reliability. Clearly, these efforts are founded in good intentions, and many such programs enjoy considerable success. Still others languish due to a lack of symmetry and central focus. Money is spent and efforts expended, but results are too often disappointing. Condition monitoring requires a proper foundation from understanding and aligning criticality and failure mode analysis. Align- ment greatly helps to optimize deployment of activities and spending to minimize waste and redundancy. Alignment also keeps the maintenance and reliability professionals on the same page by providing a clear under- standing of what's being done and why. This column is Part 3 on this topic. You can find Parts 1 and 2 at Machinery- Lubrication.com under the archive tab. In Part 1, "A New Look at Criticality Analysis for Machinery Lubrication" (April 2013), I discussed the concept of Overall Machine Criticality (OMC) and its importance on a wide range of decisions relating to machinery lubrication and oil analysis. When optimized, these decisions define the Optimum Reference State (ORS) needed to achieve the desired level of machine reli- ability. It is intuitively obvious that smart maintenance decisions require a heightened sense of both the probability and conse- quences of machine failure. Part 2, "Don't Forget Lubricant Criti- cality When Designing Oil Analysis Programs" (April 2014), explained how there are consequences when lubricants fail that are, at least initially, independent of machine failure. These include the lubricant replacement costs (material, labor, flushing, etc.) and associated downtime. These costs can exist in the presence of a perfectly healthy and operating machine. Of course, lack of timely replacement of a defective lubricant will invariably lead to dire machine failure consequences. For some machines, these cascading events can produce enor- mous collateral damage and financial hardship to an organization. To my knowledge, the method presented in this article is the first truly rationalized and unified approach to condition moni- toring based on both machine and lubricant failure mode ranking and criticality anal- ysis. The condition monitoring methods and technologies being integrated include oil analysis (real-time, portable and labora- tory), field inspections (advanced methods providing frequent and comprehensive assessments), and other portable and real- time condition monitoring technologies (thermography, vibration, etc.). This approach is important enough that it deserves a name: Unified Condition Moni- toring (UCM). What makes UCM different from other strategies is the following: 1. Periodic condition monitoring technol- ogies and methods for each machine are integrated and optimized. 2. Periodicity for each technology and method is optimized. 3. The method of optimization is based on criticality analysis and failure mode ranking. Failure Mode Ranking Ranking failure modes helps customize and optimize the condition monitoring strategy. This is another way to say gaining the greatest benefit for the least possible cost and risk. According to the Pareto principle, AdVANtAges of a Unified CoNdItIoN moNItorINg Approach m a i n t e n a n c e a n d r e l i a b i l i t y JIm FItCh NorIA CorPorAtIoN Figure 1. The relationship between machine criticality and lubricant criticality