©
Acceptability criterion in inspection by variables
  Applies ANSI/ASQC Z1.9-1980, "Sampling Procedures and Tables for Inspection by Variables for Percent Nonconforming".
2024.Nov.25 05:15:04
n Sample size.
L, AQL(L) % Lower specification limit and its AQL.
U, AQL(U) % Upper specification limit and its AQL. •
X Measurements:
  Determines the acceptability of a lot through sampling by variables according to the standard ANSI/ASQC Z1.9-1980.
  Both k and M values are those in the standard (not calculated from the risks here).  As to the "estimation of the lot percent nonconforming" (pL, pU, pT), it is calculated (not by consultation of the table in the standard), small differences from the manual procedure being thus possible.  (For too small quality indices, which lead to an inacceptable argument for the Beta function, the estimates are made 100 %.)
References:

• Anonymous, 1980, ANSI/ASQC Z1.9-1980, American Society for Quality Control, Milwaukee, WI (USA).

• Resnikoff, G. J., G. J. Lieberman, 1957, "Tables of the non-central t distribution: density function, cumulative distribution function and percentage points", Stanford University Press, Stanford, CA (USA).

 
 
Valid HTML 4.01! IST http://web.ist.utl.pt/~mcasquilho/compute/qc/F.AcCritVar.php
Created: 2003-06-23 — Last modified: 2007-10-11