Forum: Reliability & Maintainability Questions and Answers
Posted by: Xiangping,Wu (email@example.com )
Organization:SHENZHEN HUAWEI TECH.CO.LTD.
Date posted: Thu Sep 16 2:51:17 US/Eastern 1999
Subject: Software Reliability Prediction
I have just bought the book of Reliability Toolkit:Commercial Practices Edition from RAC.I have some questions on the method of software reliability prediction in it.First,in this book,only seven programming languages'expansion ratios are provided.Does anyone could give me the expansion ratios of other programming languages(e.g.VB,VC++,DELPHI,etc.)? The second question is I found when predict a software' initial failure rate by this method,the result is only related to the host processor speed and the programming language used,but have nothing to do with the length of the code.That is,a software has 20,000 lines of code and a software has 200,000 lines of code will has the same failure rate.Does anyone could explain it? Thank you.
Posted by: Chuck Ramsey (firstname.lastname@example.org )
Organization:ORNL Research Reactors
Date posted: Fri Sep 10 14:30:54 US/Eastern 1999
Subject: High speed gas circulator with magnetic bearings
Does anyone have or know where I can turn for recent information on the reliability and performance of high speed gas circulators, variable speed controllers, and/or magnetic bearings and their control unit? The circulators are intended operate over a speed range of 7000 to 40000 rpm in a hydrogen loop and temperatures from ambient down to 20K. Any input is greatly appreciated.
Posted by: RS Moore (email@example.com )
Date posted: Thu Sep 9 11:24:09 US/Eastern 1999
Subject: Life assessment for thermally shocked product
My company has recently undertaken thermal shocking of a small (0.6" x 0.6") hybrid-like device. This involved 450 thermal cycles from -50C to +90C in 60 seconds with 30 minute temperature dwells at each extreme. The product was unpowered.
Am I able to determine an estimate for the product's life based on the testing described above and if so how do I go about it? Thanks, Bob
Posted by: Zhili Kuang (KZLKP@163.net )
Date posted: Wed Sep 8 4:37:02 US/Eastern 1999
Subject: MTBF assurance testing
The MTBF assurance testing method is provided by MIL-HDBK-781. I do not understand its principle and engineering application. Would you offer the articles, your experience or research information? Thank you very much for your help. Zhili Kuang
Posted by: Floyd Kreuze (firstname.lastname@example.org )
Date posted: Fri Sep 3 15:31:42 US/Eastern 1999
Subject: BIT Demo Accept/Reject Criteria
What do respondees suggest as a good way to determine a set of accept/reject criteria for BIT Demo Testing? Is this topic covered in any technical book or article?