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  • 1.  Reliability Prediction for equipment that has not failed yet

    Posted 10-18-2018 05:29 AM
    Edited by Chandra Salim 10-18-2018 05:41 AM

    Dear all professionals,

    I met some cases in reliability performance monitoring that calculated using statistics distribution upon equipment's failure history.

    And I am now looking for any chance to calculate reliability prediction on equipment that has not failed yet during operation time.

    Yes it is referred to use international database such as OREDA, NPRD, EPRD, etc. as common case, yet it is somehow bother my mind that there used to be a way to calculate some aviation equipment which has high MTBF from its fabrication production and has met no failure history at all ever since the fabrication process began.
    I am about to get some opinion and experience sharing from all of you.

    My best regards



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    Chandra Salim
    M.Sc.
    Bandung, Indonesia
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  • 2.  RE: Reliability Prediction for equipment that has not failed yet

    Posted 10-19-2018 07:33 AM
    Chandra,

    Refer to the eta and beta value ranges in the table found at Weibull Reliability Database For Failure Data For Various Components
    Barringer1 remove preview
    Weibull Reliability Database For Failure Data For Various Components
    Weibull database of equipment failures with characterstic life (eta) and shape factors (beta)for industrial equipment
    View this on Barringer1 >
    . You could start with the typical values for the specific type of equipment you are analyzing.

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    Stephen Cooper
    Asset Management Specialist
    GRU
    Orange Park, FL
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  • 3.  RE: Reliability Prediction for equipment that has not failed yet

    Posted 10-19-2018 08:45 AM
    Chandra

    So far as the equipment that has not failed yet and the aviation industry, which also goes with most manufacturing of product, that is usually developed in the design stage often with accelerated aging tests.  On the electric machine side, for instance, there are standards for accelerating the age of components that provide a baseline and then other standards and methods for providing estimated life expectancy to a level of confidence.

    For electrical systems, in general, IEEE performed a number of studies on electrical systems and their causes of failure (since 1955).  These are found in IEEE Std 493, "IEEE Recommended Practice for the Design of Reliable Industrial and Commercial Power Systems," also referred to as the 'Gold Book;' and, IEEEE 3006.8, "IEEE Recommended Practice for Analyzing Reliability Data for Equipment Used in Industrial and Commercial Power Systems."  Both carry MTBF data on electrical systems - which, I find interesting, have not changed significantly over the years based upon industry surveys and the working groups (both standards have recently been updated and voted on).

    There are also quite a few US military guides, handbooks and specifications that are publicly available.


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    Howard W Penrose, Ph.D., CMRP
    2018 SMRP Chair and
    President
    MotorDoc LLC
    Lombard, Illinois
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  • 4.  RE: Reliability Prediction for equipment that has not failed yet

    Posted 10-19-2018 02:37 PM
    Calculators for zero failures are provided in the "Tools" section of the website named "KSC Reliability."  The calculators: (1) Are Excel based, (2) Do both data types (time-based failures and demand-based failures), (3) Do both statistical schools of thought (classical and Bayesian) and (4) Provide examples.  Let me know if this satisfied your need.  Tim.Adams@NASA.gov

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    Tim Adams ASQ CRE
    Reliability & Risk, Senior Engineer
    NASA Kennedy Space Center
    Kennedy Space Center FL
    Website: "KSC Reliability"
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