"Last but not least: also quality requirements have to be made checkable by adding acceptance criteria to them." I would suggest to rather use the terms "verifiable" (in analogy to IREB vocabulary) or "testable" (as in INVEST) instead of "checkable" ---
"Last but not least: also quality requirements have to be made checkable by adding acceptance criteria to them."
I would suggest to rather use the terms "verifiable" (in analogy to IREB vocabulary) or "testable" (as in INVEST) instead of "checkable"