ajaykumar asked 15 years ago

Dear Sir,
1)I am Calculating the Failure Rates using MIL-HDBK-217FN2.
In this the Memory Size has given upto 1MB only. But my Parts having 128MB,
1GB And 8GB. Could you please give suggestion to calculate this problem.

2 Answers
smorris answered 15 years ago

When a part has a complexity beyond that listed in MIL-HDBK-217, I typically use the most complex category available. Some might argue that you should extrapolate the old models; however, in general this will provide very pessimistic results. Generally speaking, component manufacturing has gotten a lot better since the MIL-HDBK-217 models were published (1995), so even though the handbook does not directly cover some of the more complex microcircuits available today, I believe the failure rates obtained using the above approach are the best engineering estimates until such time as new studies are conducted. Document your assumptions in the reliability analysis report.

mjhudston answered 15 years ago

The issue with 217F N2, is that it has not been updated (and will not) since the early 1990’s. I often question its relevance with technologies today, since the quality of manufacturing has increased markedly since then.

Unless you are required to use 217FN2, I would consider more modern models, such as 217Plus.

Either that you could extrapolate, however taking that to 8gig, would indicate that the FR of 8gig is very poor.