Is it possible (and how) to combine FR predicted by two different methods: FIDES and MIL-HDBK-217F?
E.g. lambda_LRU1 = 40 [Failures per 106 Calendar hours]
lambda_LRU2 = 30 [Failures per 106 Operating hours]
lambda_SYS = ? [Failures per 106 Operating hours]
I just wrote a full answer to this topic.
But this GRR##¤&!# FFF... forum lost all my writting. I have no time and courage to type it again now. May be latter.
(just one word : the answer is yes, of course)
To combine FIDES and MIL-HDBK-217 prediction, my advice is to use the FIDES life profile and the "calendar hour" unit as the reference.
Extract from the MIL-HDBK-338. A similar table exists for temperature conversion.
Remember that this comes from MIL-HDBK-217. FIDES reacts in a different way. MIL-HDBK-217 says that components will fail anyway, randomly. FIDES says that the environment physicaly produce failure.