TQA (TOTAL QUALITY ASSURANCE) IS A FUNCTION OF CONTROL

Linguistic quality assurance - especially translation quality - can only be the result of checks, lots of checks. When linguistic quality (terminological relevance, socio-stylistic rigor, and geo-stylistic coherence) and the graphical and typographical beauty of the layout (layout and illustration) have to be "produced jointly", the number of crosschecks is multiplied.
So-called "zero error" requires it!
This is why the Eurologos production process covers, and necessarily repeats, what the ISO 9000 calls the "quality loop": the classic sequence of production - check - corrective action - check - validation.