Actually, it is going to mostly depend on what class of medical device it is. Soft goods likely are Class 1 or 2. I don’t think I have seen a soft goods Class 3, but never say never. Once a class is determined, is it 510K exempt or not? It is likely to be exempt, but not always.
The class and your FMEA will drive your specification. The specification will drive the QTPs for production and incoming. As the “engineer”, you will be responsible for determining the QTPs, but you should be getting guidance from your regulatory and legal departments.
If your product is not a device, the FMEA will drive your specification alone. No different between hard goods and soft goods really, just different forms of failure. For example failure at a stitch seam versus at a knit line.