The term scheme performance is used here in a very restrictive sense. Scheme performance is defined as the composite proportion of lots accepted at a stated percent nonconforming when the switching rules are applied. Analogous curves and other measures of overall scheme per- formance when the switching rules are used are given in Tables XI, XII, XIII, XIV, and XV.
Those for the individual plans that represent the elements of the schemes are presented in Tables V, VI, VII, IX, and X. Operating characteristic curves and other measures of per- formance presented in this standard are of two types. Incorrect application can result in regulatory observations.ġ1.1 OPERATING CHARACTERISTIC CURVES. Therefore, it is very important to properly interpret the standard and apply the inspection rules as they are prescribed. The common mistakes include, but not are limited to, the selection of incorrect sampling size, selection of incorrect acceptance criteria, or attribute plan used for variable data, etc. The standard provides instructions on how it is supposed to be applied however, it is often misinterpreted. The use of sampling tables provides a quicker way of selecting the sampling plan instead of developing a sampling plan using complex statistics. ANSI/ASQ Z1.4- 2008: Sampling Procedures and Tables for Inspection by Attributes is an acceptance sampling system that provides tightened, normal, and reduced plans to be applied for attributes inspection for percent nonconforming or nonconformities per 100 units. It is a common pharmaceutical industry practice to employ American National Standards Institute ” ANSI)/American Society for Quality ”ASQ) Z1.4-2008: Sampling Procedures and Tables for Inspection by Attributes for inspection of product/process defects. Attribute sampling plans are often used to inspect the effectiveness of the product/process and to determine the rate of compliance with established criteria.