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: Andrew Rowland
Date posted: Mon Nov 4 11:20:38 US/Eastern 2002
Subject: Weibull Analysis Results
I am analyzing field failure data of an electronic system. When performing a Weibull analysis, I find a beta of 0.952 with 19 samples. The source of information is only accurate to the day (i.e., I only know what date a failure occurred, not exact time), so I expected some error from this. Given the age of the equipment being analyzed, it would be expected to be operating within it's useful life. How far from 1.00 does the beta need to be before I would be wrong in using an exponential distribution? How much error can I expect due to the time reporting limitations of my data source?
Subject: Weibull Beta Confidence
Reply Posted by: Joe Dzekevich
Date Posted: Tue Nov 5 16:45:14 US/Eastern 2002
All good points made. I agree. Now, just like you can construct confidence bounds around the Weibull characteristic life, you can also construct confidence bounds around the shape factor, Beta. That should help you to see how far the spread is above and below 1.0.