Two shelves, identical drawings. One cut to a tenth of a millimetre, one cut by a person who had done it four hundred times and stopped measuring somewhere around the ninetieth.
Nobody could tell
We put both in the corridor for a fortnight and asked everyone who walked past. Eleven people guessed. Five were right, which is the number you get from guessing.
- The machined edge cost four times as much
- The hand-cut edge took eleven minutes longer
- Only one of them had a story anyone wanted to hear
We kept the tolerance where it does work — the joints, the runners, anywhere two parts have to agree. We dropped it everywhere the only audience was the drawing.