I would like to add two important points to the others:

• Have a clear understanding of what a tolerance or other limiting specification is and why it is important.
• Able and willing to learn.

The reason for this is me having, in the past, to spend several hours with a member of the QA department who had "stopped the line" due to a component being "not to drawing" as a result of a supplier having delivered, at no extra cost and with appropriate wavers, resistors that were 1% tolerance rather than the ordered 3% tolerance ordered but in every other aspect exactly what was ordered. Eventually he agreed to sign off on restarting production only to do the same thing a week later with a batch of capacitors that came in, again with all of the paperwork, but with a 5% tolerance rather than 10%.

Obviously this was a hardware issue but I can well imagine a similar problem where a software vendor is expected to deliver a component sub-system and the requirements specify permitted and expected size and execution times or a range of compatible OSes and the vendor delivers better than expected, e.g.: Required operating system compatibility: Windows 7,8, 10 & 11 but delivered certified to work on all windows version 3.11 through 11, OS-X 6+, RHEL 5+ - i.e. the requirements exceeded rather than simply met.