New Product Development - Additional Protection From Unknowns

I thought I would lay out some of the things that I think are needed to have a chance for a clean launch of a new product.
I have started to discuss PFD and PFMEA and there is more to come on that. In addition to those two essentials, there are some other tools that can reduce the risk of an unknown problem from slipping through to the customer.
Remembering that the PFD defines the intended process and the PFMEA picks apart things that might go wrong, and why, we have the fact that humans are fallible and mistakes and omissions will be made. We will not be able to 100% determine all of the prevention and detection controls in advance. How do we protect ourselves from these "unknown"risks?

Here is a list.