According to the lectures,

Process Validation according to the FDA is defined as "results of a process cannot be fully verified by subsequent inspection and test."

And process validation according to ISO is defined as "processes for production and service provision where the resulting output cannot be verified by subsequent monitoring or measurement."

As Dr. Simon mentioned that these leave a lot of room for interpretation resulting in audits requiring changing your protocols or processes etc.

My question is what are some examples where a product was on the market for a very long time and all of a sudden you get an audit requiring you to take it off the market. What processes or chain of events will you have to go through to get your product or device back on the market while fixing the issue by FDA or ISO standards. What is easier to work with FDA or ISO audits?