I know. And I wasn't. These are real life possibilities and knowing the answers can be helpful.

We see this in my line of work, engineers design a system and forget about common variables. Example from a few years ago was an update to a forklift transmission, the factory wanted to use a valve body from another model to save costs. Two very different transmission designs and the valve worked fine in it's original application.

The engineers never considered internal leakage in the receiving transmission and pressures were all over the place. Mechanics had to play with springs and orifice sizes to get it functioning.

A fellow at a fab shop that built fairly large structures mentioned that a new design ended up almost an inch out of spec. The designers had all the parts laser cut to some exact dimensions. But they completely forgot to leave space for welds. Lots of grinding followed on the rest of the first batch while the plans were redrawn for the laser cutting.