Before the recent move to quality control by US auto manufacturers, about 25%of the assembly workforce was engaged in repairing defects when the autos rolled off the assembly line. The old style quality control, at which the Germans are the masters, was to have teams of inspectors at various stations and test the products. Because QC was thought to require additional workers, QC was considered an added cost. In the 1930s the concepts of statistical quality control, SQC, were invented in the US. After WW II, Deming and Juran, SQC experts, could not convince US manufacturers to adopt SQC.
Deming and Juran then went to Japan where they were treated like heroes as the Japanese manufacturers rapidly adopted SQC, which enables manufacturing engineers to identify problems in the production process without inspectors. The new style Japanese approach to quality control is to use better methodology-statistical quality control and to design quality into the product rather than determine the quality after the fact using inspectors. To make continual improvements in quality a permanent part of the factory Japanese managers organized workers into quality circles where through weekly meetings ideas from the plant floor were reviewed and the best ones implemented. By eliminating the need for repair workers and inspectors, the new approach saves money and creates satisfied customers. Such an approach to quality control is necessary to run JIT inventory control.
Current the Europeans have created in international quality standard called ISO9000. Many US firms are becomming certified as having meet these standards.