But you can't push a machine beyond its design limits.
Funny thing about design limits. Take a look as the Mars rover Spirit for example. It was designed to last 90 days, or 3 months. But, it went pass its designed limit to last over 6 years. If there was a repair shop on Mars, it could have done another 6.
Yes, but it's a rare special case. It was a research project where the requirements were not exactly known and more important, the bean counters were not allowed to exerсise their full power. When that public is kept on a tight leash, the things can be made really good.
I do remember my first job in the electronics industry in mid-seventies, right after the college. It was at a small manufacturing facility of the R&D center. The plant manufactured a precision on-board time keeping devices for the first satnav system (something like US' Transit). All the boards were assembled manually by the large teams of girls. And there were a guys like me, who were measuring and tuning the boards for required performance characteristics. As a freshman, I was assigned to a simple work, the 5 MHz buffer amplifier board. I had to measure the parameters like output amplitude, clear factor, power consumption, etc. in the range of power voltage and ambient temperature. There were no pots and the tuning method was to change the values of res and caps. For the temperature testing, I had to roll a huge temp chamber to my workbench and put the board inside. Some of that chambers were automated, while in others, the temperature controller was broken or missing so it was necessary to change the temperature manually, as appropriate. On the top of every chamber, a device was located that recorded the temperature profile on the paper roll, which was later archived with the other paperwork for that particular amplifier board. Funny, the board was for placement inside the vacuum glass vessel next to the oscillator board so it was for working at a constant temperature. Nevertheless, I had to measure all the parameters in the temp range from -60 to +70 C. Then, I had to submit the board to the soldering lady to install the tuned components professionally. The first document, with a signature of both sides. Then the vibration testing, one more form, that specified the G number, the waveform type and the time interval. Then the form for conformal coating (the coating type and the number of layers). Then go to the visual inspector, who had to officially make sure that every soldering joint is good, there is the space grade marking on every component, and the coating is OK. Then the form for overmolding the board with foam (the foam type, the outer dimensions). Then I'd to perform the measurements all over again, to finish the paperwork and to declare the work done. No wonder that in the end the paperwork overweighted the board itself. I think it's not much different in the other facilities in the world where that sort of equipment is manufacturing. Not a commercial application.