Plant Services - August 2007 - (Page 29) ASSET MANAGER Critical assets The CMMS can help you define, rank and maintain them in the right priority ou can ease into the workload that reliability-centered maintenance, condition-based maintenance and root cause analysis represent while reaping the benefits in the process. Focusing on critical assets maximizes the return on any effort, regardless of the technique you select. Critical assets represent an opportunity to meet customer needs, mitigate risks and ensure regulatory compliance. But you need to know the differences that determine asset criticality. Additionally, various CMMS features and functions can help you through the process. Y tional if you’re going to avoid a bottleneck that slows production. For example, printing presses are critical assets. When they’re not running at full capacity, it affects quality, cost of goods produced and delivery schedules. High criticality means the effect of failure is catastrophic health, safety, environmental, customer-related or financial consequences; bottleneck analysis reveals that the process is highly dependent on this asset. Low criticality means effect of failure is low or negligible; bottleneck analysis reveals that the process isn’t particularly dependent on this asset. Asset criticality Determining criticality can be a subjective Treat critical assets differently than non-critical exercise, but you can be somewhat more ob- Calculating asset ones. Just as you classify spare parts using the jective by calculating the effect of failure and criticality helps ABC or XYZ classification system to identify determining which piece of failed hardware high-volume or high-value parts, so should you to prioritize the classify assets to ensure you’ll expend resources, has the greatest consequences. The subjectivuse of scarce ity of this approach is in comparing the contime and money on the more important ones. sequences. For example, rank the severity of Examples of procedures and techniques that faresources. these consequences: vor critical assets are as follows: • A minor delivery to an important customScheduling for assets with a higher critier might be a day late cality should be given priority. Assign the better resources, • A large delivery to a few small customers might be a sooner in the queue, and with more careful follow-up. week late Repair/replace decisions depend on criticality. The • A person might be injured, resulting in at least one day greater the criticality, the easier it should be to get maintelost time nance funding because it’s more important to bring critical • Minor quantities of a toxic substance might leak into the assets closer to the “as new” condition compared to nonmunicipal sewer critical assets. Given unlimited dollars to spend on maintenance, rankLife-cycle costing is another consideration. Many assets ing them is probably a non-issue. A lack of unlimited reare justified on the basis of the initial capital outlay when sources means calculating asset criticality and prioritizing. they’re replaced. Tracking the total cost of ownership or These four consequences can be considered critical, not catlife-cycle cost gives a more accurate costing over its lifetime astrophic or negligible, so one must judge relative criticality and includes salvage value. This might not be worth the efon a case-by-case basis. For example, how important is that fort for non-critical assets, but life-cycle costing can reveal customer? How small is a “minor delivery?” How impordifferences of millions of dollars for critical assets because of tant is a “large delivery” relative to the important customer? variations in the cost of maintainence. Which has a higher priority – customer impact or health, Maintenance programs are of three types. These are safety or environmental problems? failure-based (run to failure), use-based (maintenance at Another tool for determining criticality is bottleneck analregular intervals of time or usage) or condition-based (preysis, which identifies opertional dependencies by mapping a dictive maintenance). CBM usually is the most expensive critical path for each process flow to highlight relationships. of the three but is more likely to be cost-justified for your Higher criticality assets are those that need to be fully operacritical assets. August 2007 www.PLANTSERVICES.com 29 Critical versus non-critical http://www.plantservices.com/voices/asset_manager.html http://www.PLANTSERVICES.com
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