Category Archives: CBM

Condition based maintenance

Non-rejuvenating events

By definition a Non-Rejuvinating Event (NRE)  is an action that systematically affects condition monitoring value levels, but does not add “life” to (i.e. reduce the physical age of) the asset. For example, if immediately after greasing the bearing, there is a … Continue reading

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Defeating CBM

The following slide presentation on the importance of distinguishing failures from suspensions on work orders,  refers to the Proportional Hazard Model (PHM) and the shape parameter β. The shape parameter is calculated from a good sample of condition monitoring and … Continue reading

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TBM or CBM?

In a fleet of over one hundred units there are four spare engines.  Should an age based overhaul policy be used? Scheduling overhaul based on age seems appropriate due to the need to level the load in the engine rebuild … Continue reading

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PF interval from the failure rate

How can the PF interval be determined from the failure rate? You can’t know the PF interval directly from the failure rate. The PF interval is unrelated mathematically to the failure rate. It is the lead time between the ability … Continue reading

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EXAKT vs Weibull

The difference is that Weibull is a reliability analysis procedure in two dimensions, namely Reliability versus Age. Its main purpose is to discover the relationship (equation) relating reliability and age. EXAKT is a reliability analysis software that relates several dimensions, … Continue reading

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