MMC assemble the cars using bought in components where they do not wish to manufacture in-house. Sensible good practise is to have an agreed quality standard with suppliers based on standard QA procedures. Spec, manufacturing process, testing, batch ID etc. This after supplier assessment and drilling down through them to sub contractors. Regular monitoring SHOULD then significantly reduce/eliminate problem components. This is an evolutionary process with built in future development included. Sampling plans for testing are properly set up ( from a statistical sampling plan to 100%) with batch pass/fail. Failed batches can be isolated and 100% tested. Regular monitoring of supplier quality is an important inclusion, getting customer/supplier relations on a good footing. Building trust and reducing costly problems. That’s the over simplistic basics. Good QA/QC is designed to give end product quality AND manufacturing credibility to maintain the required standards. Just to add....in the CX cars brake issue the cause could have been anywhere in the chain from top to bottom. Clearly the cause was missed. That would be the investigation target. Why it happened? Reason? Components affected, resolution to prevent future problems.
