BS ISO 3951-1:2013

Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols
5 Acceptance quality limit (AQL)
6 Switching rules for normal, tightened, and
   reduced inspection
7 Relation to ISO 2859-1
8 Consumer protection
9 Allowing for measurement uncertainty
10 Planning
11 Choice between variables and attributes
12 Choice between the s-method and sigma-method
13 Choice of inspection level and AQL
14 Choice of sampling scheme
15 Preliminary operations
16 Standard procedures for the s-method
17 Standard procedures for the sigma-method
18 Procedure during continuing inspection
19 Normality and outliers
20 Records
21 Operation of switching rules
22 Discontinuation and resumption of inspection
23 Switching between the s-method and sigma-method
24 Charts B to R - Operating characteristic curves
   and tabulated values for single sampling plans,
   normal inspection: s-method
25 Charts s-D to s-R - Acceptance curves for combined
   control of double specification limits: s-method
Annex A (normative) - Table for determining the sample
        size code letter
Annex B (normative) - Form k for single sampling plans:
        s-method
Annex C (normative) - Form k for single sampling plans:
        sigma-method
Annex D (normative) - Values of f[s] for maximum sample
        standard deviation (MSSD)
Annex E (normative) - Values of f[sigma] for maximum
        process standard deviation (MPSD)
Annex F (normative) - Estimating the process fraction
        nonconforming for sample size 3: s-method
Annex G (normative) - Single sampling plans of Form p*
Annex H (normative) - Values of c[U] for upper control limit
        on the sample standard deviation
Annex I (normative) - Supplementary acceptability constants
        for qualifying towards reduced inspection
Annex J (normative) - Procedures for obtaining s and sigma
Annex K (informative) - Consumer's risk qualities
Annex L (informative) - Producer's risks
Annex M (informative) - Operating characteristics for the
        sigma-method
Annex N (informative) - Estimating the process fraction
        nonconforming for sample sizes 3 and 4: s-method
Annex O (normative) - Accommodating measurement variability
Bibliography

Provides the primarily designed for use, where the inspection procedure is to be applied to a continuing series of lots of discrete products all supplied by one producer using one production process.

This part of ISO3951 is primarily designed for use under the following conditions: where the inspection procedure is to be applied to a continuing series of lots of discrete products all supplied by one producer using one production process; where only a single quality characteristic, x, of these products is taken into consideration, which must be measurable on a continuous scale; where production is stable (under statistical control) and the quality characteristic, x, is distributed according to a normal distribution or a close approximation to the normal distribution; where a contract or standard defines a lower specification limit, L, an upper specification limit, U, or both; an item is qualified as conforming if and only if its measured quality characteristic, x, satisfies the appropriate one of the following inequalities: x≥L (i.e. the lower specification limit is not violated); x≤U (i.e. the upper specification limit is not violated); x≥L and x≤U (i.e. neither the lower nor the upper specification limit is violated). Inequalities 1) and 2) are called cases with a single specification limit and 3), a case with double specification limits. Where double specification limits apply, it is assumed in this part of ISO3951 that conformance to both specification limits is equally important to the integrity of the product. In such cases, it is appropriate to apply a single AQL to the combined percentage of a product outside the two specification limits. This is referred to as combined control.