M·C, IST: sample size, IV

Sample size (approximately) in sampling by VARIABLES

Calculates an approximate value of the sample size in Inspection by Variables (as in ANSI/ASQC Z1.9-1980).

AQL, α

%; %

AQL and α, both in percent.

LTPD, β

%; %

LTPD and β, both in percent.

This procedure is based on simplistic assumptions and should be used with care. The exact procedure has to be solved numerically and gives rise to a rather lengthy computation. The formula used here is:

For instance, compare the result (n = 61) obtained in the case given above with Letter J (n = 35) in the standard.

(18-Aug-2003)

References:

• Daudin, Jean-Jacques, Charles S. Tapiero, 1996, "Les Outils et le Contrôle de la Qualité", PIQ Poche, Ed. Economica, Paris

http://web.ist.utl.pt/~mcasquilho/compute/qc/F.ssizevar.php
Created: 2003-08-18 — Last modified: 2007-10-08