Am Mon, 28 Mar 2016 01:32:03 +0200 schrieb Attila Kinali <att...@kinali.ch>:
> Yes, the MTBF is a very simplicistic measure and there are a couple > of assumptions in its calculation which do not hold generally (or > rather, it's rather seldom that they hold). Yet it gives a number to > something that is otherwise relatively hard to measure and the number, > even though flawed, makes it possible to compare different devices > on their reliability. As this is more a rule of thumb comparison, > you shouldn't read too much into a 10% difference. Yet a 100% > difference is significant, no matter which of the assumptions do not > hold. > Umm, well, even a 100% difference still might mean nothing if the derivation of MTBF between different devices is based on different assumptions. That both these derivations might be seriously flawed does not help at all. Yet, even MIL-Spec parts documentation does rarely contain sufficient detail to assess the validity of the numbers in a certain application. At the very least, one would need to know acceleration factors for the different failure mechanisms, and shape parameters of the failure-vs-time plot. This kind of data I wouldn't expect to find outside the manufacturers premises, and even there it's not likely to be accessible if it exists at all. Best regards, Florian _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
