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: John Sine
Date posted: Fri Aug 18 11:24:55 US/Eastern 2000
Subject: First Year Multiplier
Can someone explain what the first year muliplier (per Bellcore) means and does each and every device/unit need to go through the burn-in time and temperature or can this be obtained by only running a qualification sample size at a burn-in temperature for the specific duration? If so, how big must the sample size be or is that defined anywhere?
Subject: First-Year Multiplier
Reply Posted by: Jack Farrell
Organization: Reliability Analysis Center
Date Posted: Wed Aug 23 9:27:23 US/Eastern 2000
Telecordia (formerly Bellcore) defines the first-year multiplier as "The average failure rate during the first year of operation (8760 hours) can be expressed as a multiple of the steady-state failure rate, called the first-year multiplier. The steady-state failure rate provides the information needed for long-term product performance. The first-year multiplier, together with the steady-state failure rate, provides a measure of the number of failures expected in the first year of operation." The first-year multiplier is based on the effective operating time from burn-in. It is my interpretation that in order to claim the benefits of burn-in the device/unit must have been subjected to the burn-in. You can also contact Telecordia at 1-800-521-2673.