There is correct knowledge.

Fix a computer, i do it as a hobby.

You have to KNOW what to do, so that it DOESN'T DO THAT FAIL AGAIN.

And if it a different problem shows up, you fix that problem, so that problem doesn't show up again, until %100 stability is maintained, which generally gives the scenario of the computer staying running for 360 days without an error... that's pretty fucking fail proof, and not unheard of.

And it can be exercised onto different topics, like an electric generator engine, built and tweaked and diagnosed so it remains a reliable source of power for say a hospital.

OP has Failed.

You cant blame the Decay rate of molecules and solid metals of 3rd dimension as a inclusive of "FAIL PROOF" things in life.

Its starts fail proof (brand new item) but 3rd dimension decays that item, not the creator of that item.

And what if 3rd dimension rate of decay slowed dramatically?

nothing is fail proof from 3rd dimensional decay rate.