Hopefully this is not a classroom test question.
The requirement has to do with the fact that in the O&G sector, specially when dealing with deep water technology, some suppliers are extremely reticent in disclosing parameters about their products, making it almost a "black box" purchase.
So in the context of critical supplier qualifications, it behooves the organization in determining how they will accept product when acceptance and performance criteria be might sensitive and proprietary to the supplier.