Test, review, test! It doesn't need to be a long post about nothing. Some things will fail no matter how much you prepare! Having a vendor that will back you and replace it if things go wrong is what you need!

“Test, review, test!” - I agree with colleague Casey. And I would make a partnership proposal incentivizing the vendor through bonus amounts in contracts, managed by KPI controls. By involving the vendor in this commitment to KPIs, it would also be possible to work on a partnership to involve the vendor more in learning and taking action on quality problems that occur, strengthening the idea of consolidating quality maturity

First thing I do is make sure there’s a proper agreement in place with vendor SLAs and all, so they can’t delay or send low-quality stuff just like that. If they miss service levels, I keep record and raise it immediately. Also, every time repair happens, I ask team to check quality properly, not just blindly accept. Sometimes small issues repeat, so we keep tracking it. And if same vendor gives trouble again, I keep 1 , 2 backup vendors handy—just in case. Better to be ready than sorry, no?