So there are essentially 2 elements to this presentation:
a) Considering the Role of Quality Assurance means What does an EASA Quality Assurance Do?
b) Maximising the Return on the Investment (Which Investment? - Essentially the Investment the Organisation makes to deliver the role of Quality Assurance)
Considering the QA - QC connection
One interpretation defines QC as “to check, test, or verify by evidence or experiments” and assurance being defined as “confidence of delivery” (maybe too narrow for our needs).