Quality control, has to be taken care of by someone in the factory who has been there long enough to know what to look for. This may be part of the problem. Workers need to take pride in their work, and management needs to give them time to do quality work, not just daily piece allotments. I have herd that at some of the rv production lines, if a worker gets their allotment done early than they can go home for the day. This makes for sloppy work,
The dealer we purchased from told us they could not hire and train new techs fast enough to keep up with the demand and after they train, many leave to go to higher paying dealers.
