SRC Forum - Message Replies
Forum: Reliability & Maintainability Questions and Answers
Topic: Reliability & Maintainability Questions and Answers
Topic Posted by: Reliability & Maintainability Forum
Organization: System Reliability Center
Date Posted: Mon Aug 31 12:47:36 US/Eastern 1998
Posted by: swami
Date posted: Thu Jun 15 16:20:22 US/Eastern 2000
Subject: bellcore/mil217 values
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 ?
Subject: Mil-Hdbk-217, Bellcore Failure Rates
Reply Posted by: Jack Farrell
Organization: Reliability Analysis Center
Date Posted: Wed Jun 21 13:59:11 US/Eastern 2000
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.