There is that. Unless it's a giant structural flaw you can usually get it fixed, or at least the part replaced, though, or I thought so.

I will have a read of that. Thank you!

Yep, or at least work around it. Individual parts are often redesigned to eliminate flaws, and will be replaced (depending on severity) at each plane's next scheduled inspection or on immediate recall. In many less severe cases the flaw will simply be documented on the maintenance schedule as a "check this other place for cracks too - if you see any replace part 1234ABC". As I said, very conservative, so if they can characterise the failure mode and have a reasonable idea of how long it will take to progress from first symptoms to critical failure, they'll stick to the devil they know rather than replace it with something they have no operational data on.