you write an ECN (Engineering Change Notice). these stack up against a given part number (controlled by a drawing). then the drawing gets updated. this is wh

you write an ECN (Engineering Change Notice). these stack up against a given part number (controlled by a drawing). then the drawing gets updated. this is where any conflicting ECN's get discovered. Note: ECN's were how things worked when you had a draftsman. Most engineers do the CAD themselves nowdays.