In “An undetected error“†, Russell A. Kirsch states “the Kirsch postulate”:
All computers are always, in some sense, “broken.”
How he reached to that assertion is an interesting story that includes moving the SEAC, a logic (wiring) error found out during the move and a lot of debugging that really missed the error.
[†] – “Letters,” Computer, Vol. 42, 04, pp. 6-7, April, 2009.
Managing organized complexity 
tshh, το ’90 έλεγα “on the internet nothing works all of the time “