It depends to the acceptable risk level in your company. Usually AFR=10 is acceptable in most companies.
AQL - acceptable quality level
It is conventionally 5% (or lower) but there is no good reason for that level.
By practice, understanding. and revision
You study, understand and practice - as with any other subject.
The answer is a Threshold Value
The "acceptable noise level" will depend on your specific needs! What is "acceptable" in one situation, may be utterly unacceptable in another.
A decision based on what constitutes an acceptable level of risk
It depends to the acceptable risk level in your company. Usually AFR=10 is acceptable in most companies.
Couple percents.
AQL - acceptable quality level
It tries to attain an acceptable level of veracity.
40-45db
It is not a level indicating diabetes but pre-diabetes.
one percent
acceptable error level
be repeated until performace is at an acceptable level