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: Victor Lago
Date posted: Tue Mar 2 4:19:00 US/Eastern 2004
Subject: Item Toolkit - Memories
I have a problem with the memories size using the Item Toolkit. This application only permits memories up to 1001 bit, using MIL-HDBK-217 Notice 2. The equipment which I have to calculate the failure rate, contains memories higher than these 1001 bits.
The only idea I had was to calculate the failure rate for these chips, with the MIL-HDBK-217 Notice 2, and after adjust them taking the "Adjustment Factor". Anybody knows another way to resolve the problem.
Thank you all.
Subject: Memory Failure Rate Prediction Tools
Reply Posted by: BWD
Date Posted: Mon Mar 15 15:19:22 US/Eastern 2004
The database that you are using appears to 20 or more years out of date. Memory devices have increased to millions of bits and failure rates have been reduced from thousands of FITS to tens of FITS. With this in mind, I would suggest that you procure a new prediction tool that has more up-to-date reliability information. The RAC’s PRISM is such a tool.
Adjusting the failure rates and substituting into the original “Toolkit” is a possible work-around. Again I would use PRISM rates instead of MIL-HDBK-217 rates as 217 is over ten years out of date.