Category: Theory and definitions
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Is “random failure” really random?
The word “Random” might confuse us when we refer to Nowlan and Heap’s failure pattern B that describes “age independent failure”. When using the word random applied to an event, we tend to infer that the event is unpredictable. Randomness suggests a non-coherence, such that there is no intelligible pattern or combination that may be discerned. But maintenance…
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Failure probability prior to attaining MTTF
The article “What is the scale parameter” showed that 63% of randomly failing items or items adhering to Weibull failure behavier will fail prior to attaining their MTTF. Generally speaking, the MTTF is not a good decision guide for the age replacement of an item. The following shows that for age dependent failure behavior (e.g.…
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Problem statement
When to maintain? (Slides) In the casino hall that we call “maintenance” we are faced with choices. Risk is associated with each decision we take. We might say that maintenance is the art and science of managing risk. The choices we make day to day affect the organization’s bottom line profitability. Pursuing the casino metaphor…
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RCM – Living RCM: Achieving reliability from data
1 The objectives of LRCM (slides) Living RCM was created to address two vital yet unresolved issues not addressed by initial RCM or the EAM. First, observational data entered on the work order is, generally speaking, of insufficient quality for Reliability Analysis (RA) and decision modeling. Efficient maintenance management requires model based decision making. Otherwise…