Curse that sloppy worker. But today, most factory auto painting is done by laser-guided robots, not by human workers. A run or sag in a vehicle s finish is most likely the result of inadequate equipment maintenance or improperly specified materials or processes. The root cause is more likely a bad budget decision or an inattentive engineer than a slovenly worker. Because painting robots are outside of our experience, we miss that point and relate new car finish defects to what we know about painting cars, to the workers we see holding spray guns in body shops.
Management loves the new statistical realities of quality for two reasons.
After an initial investment in equipment and training, statistical quality tends to pay its own way. Better yet, it does not require pesky monitoring and adjusting of the attitudes of temperamental craftsmen. Instead of relying on inspections to reveal defects that necessitate the expensive rejection or repair of finished or semi-finished products, SPC reveals mistakes early and makes it easier to identify and stamp out their root causes. Catching mistakes earlier means less rework and rejection, reducing costs and increasing profits. It is easier to program and reprogram machines than people.