Quality Asshrance Flashcards
What is quality assurance
Making sure the measured values of the products stay as close as possible to the target value so that all of the products are of the same quality
What are sample averages or ranges plotted for
To see how far they are from the value you’d expect to see if it was running properly
Why do you use sample averages or ranges
They’ll be more closely distrusted than actual data values from the pop
So will be less variation
How far away are warning limits
Two standard deviations above and below
What percentage falls within the warring limits
95 %
How far away the are the action limits
Three standard deviations above and below the target value
What percentage falls within the action limits 
99.8
What should happen if the sample average or range lies between the warning and the action limits
Another sample is taking immediately to see if there’s a problem if it is also outside the warning limits the production should be stopped
What happens if a sample is outside the action limit
Production should be stopped immediately
