SRC Forum - Message Replies

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

Original Message:

Posted by: Johnny
Organization:Micron
Date posted: Sat Aug 31 1:08:08 US/Eastern 2002
Subject: Reliability Prediction vs Field Reliability
Message:
Why is field reliability always lower than predicted reliability? What are the various factors that contributed to that? What does it means what a reliability model is referred to as deterministic or probabilistic? what's the difference?

Reply:

Subject: Reliability prediction vs field prediction
Reply Posted by: Jean-Marie CLOAREC (Jean-Marie.Cloarec@ligeron.com )
Organization: LIGERON SA
Date Posted: Mon Sep 2 6:02:56 US/Eastern 2002
Message:
Prediction is based on compute figures and statistical traitment. Field reliability is based on reality. So there is always a difference between field and predicted reliability. The best for you is to find a conversion/learning factor between predicted and field corresponding to your application (it is not always easy to find it, but a friend of mine has succeed but his factor is not applicable to every one). So you could predicted reliability on a better basis thant only prediction. Another problem is the fact that when reliability handbook are published the technology has evolved, so the figures included are "false" or "old".