[londons_explore]

You do spot incoming QA testing.

And if you find any issues, you test the whole shipment.

And then you compare the results to the outgoing QA test results.

And if any results can't be explained by failures relating to shipping, then you fire your supplier.

You let them know ahead of time that this is the procedure you'll apply, and then they'll do proper QA testing.

[s1artibartfast]

In these industries it might take 5 years to switch suppliers. There are also specs that can't be tested at the finished good level, even destructively.

[eru]

Yes, that makes it harder.

You should probably run with multiple suppliers in the first place, so it's easier to switch between them? Of course, that extra overhead probably will eat into your cost savings.

[s1artibartfast]

People do that too, but even with all these mitigations in place, the risk just isn't worth it.

No major medical company wants to risk recalling defective product by using a disreputable Chinese manufacturer. Unknowingly selling counterfeit product is a pretty bad look to the FDA and consumers.

This is the main reason why many procurement departments have a no China policy.

[throwaway9870]

QA testing is easier said than done. There are few firms the in the world that could do complete QA testing on a TV for example.

[nazka]

Ya for instance protein supplements. If you didn’t know you have to be very careful about the origin and the process the company use to produce those. But because it’s very hard to test even with an independent testing company, you have all kind of speculation about which company to avoid and the ones that are good because you can never know. So if you see one company doing shading things or not being 100% transparent then even if the production line is fine it’s still casting enough doubt in the “expert” users to avoid to buy them. And again testing was easy then all this won’t be here. We will just test the protein powder and that’s it.

[MichaelZuo]

Mass spectrometry is relatively common nowadays It’s more likely no one wants to pay the hundreds of thousands or millions necessary to do a full test of a single supplement.