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| Browse the . . . |
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| where you'll find books on
maintenance topics from A to Z. |
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Maintenance Strategies
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Break Down Maintenance
The fix controls you, you do not control the fix. The basic strategy
is totally reactive. When things break, we fix them! |
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Preventive Maintenance
This is a time-based maintenance strategy. On a predetermined
periodic basis, equipment is taken off-line, opened up, and inspected.
Based on the visual inspection, necessary repairs are made (if any) and
the equipment is put back on-line. Some preventive maintenance is necessary.
For example, various state laws require that annual boiler inspections
be conducted. While this is a well-intended strategy, it can be very expensive
as typically 95% of the time everything was OK. |
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Predictive Maintenance
This is a condition-based maintenance strategy. This is where
predictive technologies (i.e. - vibration monitoring, infrared thermography,
ultrasonics, etc.) are utilized to determine condition of equipment, then
decisions are made about necessary repairs. This is a much more economically
feasible strategy as labor, materials and production schedules are used
much more efficiently. |
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Precision Approach
This is a concept of the future, though not any revelation. The concept
is that if we did our jobs with a mastery level of precision, then the
only failures we would have, would be wear-out failures. Maintenance statistics
support that approximately 10% or less of our industrial equipment ever
reached wear-out stage. Therefore, about 90% of the mechanical failures
we experience are "personnel avoidable events". This means the human being
has intervened in some manner that prevented the wear-out stage from being
attained. |
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Strategies to Control Failure Rates
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Reliability Centered
Maintenance (RCM)
In its traditional state, as written by John Mobrey, the goal of RCM
is to determine the criticality of equipment in any process, and based
on this information, design a customized Preventive/Predictive maintenance
strategy for the organization. This is an effort to optimize use of our
maintenance resources.
However, this is an extremely time consuming and expensive process when
done according to the text. The end result is that we become sharpened
responders, therefore still reactionary. Bottom-line results are typically
incremental and not seen for years.
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Root Cause Failure
Analysis (RCFA)
RCFA is a strategy that is based on failures that have occurred in
the past, whether chronic or sporadic. Their impact is determinable because
labor, materials and lost production is now a sunk cost. RCFA focuses on
eliminating the risk of recurrence of the failures by identifying the physical,
human and latent (organizational) system roots that lead to the failure.
Typically the worst drain on an organization?s maintenance budget is not
the one time occurrences, but the "cost of doing business" chronic failures
that are accepted. |
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| Generally 20% or less of the failure events
in any organization cause 80% or greater of the losses experienced. When
resources are dedicated to identifying these 20% of the events, an immediate
bottom-line result can be realized if they are analyzed and corrective
action taken. The accepted chronic failures stop occurring, therefore labor
hours are not assigned to them, materials are not expended and production
increased because there are no constant stops and starts of the process.
This also increases quality of product and reduces risk of safety and environmental
incidents because of the smoother running process. |
| Most costs associated with conducting a RCFA
is in people?s time and resources to verify findings. Recommendations are
generally non-capital expenditures that correct people?s decision-making
skills and the information they receive. For example, oftentimes people
need to be trained in their craft or a new technology they are using, or
we must correct an obsolete maintenance procedure or simply provide the
correct tools to do the job right the first time. |
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Synopsis
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| RCM coupled with RCFA covers all the bases
in moving towards total Failure Avoidance. RCM may be necessary to gain
control of an operation, however it is time consuming and expensive up
front. RCM?s returns are not realized quickly. |
| RCFA is real time. It deals with today?s problems
and eliminates them from being tomorrow?s problems. Bottom-line results
can be immediate if recommendations are acted on quickly. RCFA can be proactive
when accepted chronic failures that comprise the maintenance budget are
eliminated from recurring. |
| Robert J. Latino is Vice-president of Strategic Development and
a Senior Consultant for Reliability Center, Inc. Mr. Latino is a practitioner
of root cause failure analysis in the field with his clientele as well
as an educator. Mr. Latino is an author of RCI's Root Cause Failure Analysis
Methods course and co-author of Failure Analysis/Problem Solving Methods
for Field Personnel. Mr. Latino has been published in numerous trade magazines
on the topic of failure analysis as well as a frequent speaker on the topic
at trade conferences. He can be contacted at 804/458-0645 or blatino@reliability.com. |
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