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: KEITH WALKER
Date posted: Thu Aug 10 22:58:15 US/Eastern 2000
Subject: QUALITY fACTORS AND BELLCORE RELIABILITY PREDICTIONS
DOES ANYONE KNOW OF ANY SELECTION GUIDELINES FOR THE QUALITY FACTOR IN BELLCORE? I AM SPECIFICALLY INTERESTED IN THE PREDICTION OF MILITARY EQUIPMENT RELIABILITY WHEN COMMERCIAL PARTS ARE USED.
ANY TECHNICAL JOURNAL REFERENCES WOULD BE MOST APPRECIATED.
Subject: Commercial Quality Factors
Reply Posted by: Bruce Dudley
Organization: Reliability Analysis Center
Date Posted: Mon Aug 14 14:43:26 US/Eastern 2000
My comments are not directed toward "Bellcore Quality" but are general sources of data that could be of interest for this commercial part quality discussion. The quality concerns of commercially produced components have decreased in the last decade to the point where many industrial grade components are considered equal to or better than military specified ones. An international conference in 1997 on Electronic Compoments for the Commercialization of Military and Space Systems, produced numerous papers on the quality of commercial components. In particular, you should read Mr. John W. Fink of Honeywell Military Avionics paper called "Plastic ICs, An Approach to Using Them That Has Demonstrated Better Field Reliability Than With Ceramic Military Parts". This paper includes actual field data and analysis. Another source that indicates that commercial parts can have hi-reliability is the RAC report "Reliable Application Of Plastic Encapsulated Microcircuits". This report includes RAC data and analysis of plastic ICs that show reliability levels at least as good as military versions and some better. Quality and growth factors are discussed in this report.
Subject: Bellcore Quality Factors
Reply Posted by: Floyd Kreuze
Date Posted: Tue Aug 15 9:53:16 US/Eastern 2000
The most direct reply I can think of is to refer the questioner to the Bellcore TR-332 prediction document itself. Selection guidelines for quality factors applicable to all commercial parts are to be found in Table 11-3 on Page 11-20 of TR-332 [ Issue 6 dated December 1997 ]. TR-332 is obtainable from Telcordia Technologies, Inc.