Key perfomance indicators. It is how industry tracks how they are doing. Some may track things like scrap, returns, productivity, etc. They will also track supplier quality.
Supplier quailty can have extreme ramification on your business so it is imparitive to control the suppliers. Consider the frame issues posted on here (which is very small data set compared to the atcuall problem) FR and most likely other manufactures have a huge cost for warranty claims even though it will be pushed back on Lippert. It still cost FR and it is the FR name that gets hurt not Lipperts.
Most don't know who made the frame, they think it is FR and blame FR, FR name suffers but FR is resonsible for suppliers. The compnay that does the best job at controlling their suppliers will ultimately have less warranty claims and less hits to the their name. Unfortunately for some reason must companys won't put the resources to supplier quality needed so quality for their products will suffer through the supplier base.
So, looking at KPIs for both the business and the supplier base will indicate how well they do with overall quality control.
As I said I do not have any data to compare. I know all manufactures are going to have some issues but one is the best and one is the worst based on the KPIs.
The other side of it is customer satisfaction when there is an issue. More KPIs