Years ago, I worked in a manufacturing facility for heavy machinery and there was an engineer on staff who spent most of their time redoing calculations for exp

Years ago, I worked in a manufacturing facility for heavy machinery and there was an engineer on staff who spent most of their time redoing calculations for expensive parts that were machined incorrectly (e.g. an extra notch cut into the part because the machinist measured from the wrong end the first time). The updated calculations were then filed along with a new revision of the drawings that specified the part as built. I have no idea what aircraft manufacturing is like, but the idea that a part might go out the door without matching its drawing is definitely concerning. The drawing and the associated calculations are supposed to be the proof that the matter was considered, and that an informed decision was made.