Failsafe MTBF

[Karl121945]

I have a small subsystem that is used to guarentee something will not happen when it's suppose to. In determining the MTBF of the subsystem does one only add up the fail rates on components whose failure modes do not failsafe?

Thanks!

 

[IRstuff]

If the function has failed; then it's a failure. The fact that you didn't exercise it until much later is moot, unless you can guarantee that the failure will ALWAYS be exercised much later than the actual failure.

TTFN