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Forum: Reliability & Maintainability Questions and Answers

Topic: Reliability & Maintainability Questions and Answers

Topic Posted by: Reliability & Maintainability Forum (src_forum@alionscience.com )
Organization: System Reliability Center
Date Posted: Mon Aug 31 12:47:36 US/Eastern 1998

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Original Message:

Posted by: swami (swami@futron.com )
Organization:Futron
Date posted: Thu Jun 15 16:20:22 US/Eastern 2000
Subject: bellcore/mil217 values
Message:
We are trying to use data from Bellcore and Mil-Std-217 for getting failure rate data of various components. We are also interested in constructing uncertainty distributions on these failure rates. Is the value of failure rate from Mil-217 to be considered the mean failure rate of the component ? Is the value from Bellcore the mean failure rate or the 90% upper bound on the failure rate ?


Reply:

Subject: Mil-Hdbk-217, Bellcore Failure Rates
Reply Posted by: Jack Farrell (jfarrell@alionscience.com )
Organization: Reliability Analysis Center
Date Posted: Wed Jun 21 13:59:11 US/Eastern 2000
Message:
Both Mil-Hdbk-217 and Bellcore predict failure frequency caused by randomly occurring failures during any period of a systemís useful life. These failures are exponentially distributed. The useful life is that period of a systemís life characterized by a constant failure rate. Mil-Hdbk-217 expresses failure rates in terms of 1,000,000 hours and Bellcore expresses failure rates in terms of 1,000,000,000 hours.


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