> I once read a story where a prospective engineering hire was given a plant tour at Ford. He noticed an inefficiency that was costing Ford 5 cents per car. He was promptly hired.

This seems implausible at best, unless it was long enough ago that 5 cents was a meaningful amount of money. Ford only sells about 5.5 million vehicles per year, so even an inefficiency which affects every single vehicle would only cost $280,000 / year, which is almost certainly not an amount that justifies a process change across all ford assembly lines.

It's important to keep in mind what the acceptable margin of error is. It's very easy to say "no discrepancies are acceptable," but in sometimes you have a legacy system that mostly works and it's not worth the person-hours to stamp out every inconsistency.