MMC build the cars from either made in or bought in parts. Happens in nearly all industry.
Bought in....
What part do you need? Who can supply? Quality of the part? Supplier ability to make the part to the required standard?
QA plays a huge part in this, or it should!
In setting up the supply contract/terms the quality of the parts is specified, often using an agreed level of quality. In the early days this should be monitored tightly until confidence in the supplied parts is built up. Checking can then be reduced using standard sampling techniques with warning limits to trigger corrective action. Batches identified and pass/fail for each batch. This adds traceability should faults be found ( recall process initiates). Add in monitoring assembly properly to prevent bad practices/poor workmanship causing problems.
Good practice involves monitoring suppliers properly, including making sure their systems are good.
I remember visits to our steel works by Ford QA people, Rover QA and others, checking our processes, record keeping etc.
MMC are no different to any other car manufacturer. They all have failures of some kind. Toyota used to be ( still are) a leader in QA but had problems resulting in recalls, but very few as they put the effort into preventing problems. Suppliers were tightly monitored.
So, have good QA on design, supply, build, after sales. Quality problems cost money and loss of reputation. It is sensible to build in good quality and maintain it. However, many QA costs are looked on as non essential and a waste. Short sightedness and/or looking for quick cost cuts.
QA can be fun and frustrating!
I recall when QA was introduced to my workplace some 25 years or so ago. My sad conclusion was that it was more to do with records and paperwork resulting in consistent quality rather than outstanding quality. In other words, your product may not be first class but as long as it was consistently like that, and you had records to prove that approved methods were being applied, was ok.
