ISO 3951-2:2013 変数による検査のサンプリング手順—パート2：独立した品質特性のロットごとの検査のための受入品質限界（AQL）によって索引付けされた単一サンプリング計画の一般仕様 | ページ 6

3.1

inspection by variables

inspection by measuring the magnitude of a characteristic of an item

[SOURCE:ISO 3534‑2]

3.2

sampling inspection

inspection of selected items in the group under consideration

[SOURCE:ISO 3534‑2]

3.3

acceptance sampling inspection

acceptance sampling

sampling inspection (3.2) to determine whether or not to accept a lot or other amount of product, material, or service

[SOURCE:ISO 3534‑2]

3.4

acceptance sampling inspection by variables

acceptance sampling inspection (3.3) in which the acceptability of the process is determined statistically from measurements on specified quality characteristics of each item in a sample from a lot

3.5

process fraction nonconforming

rate at which nonconforming items are generated by a process

Note 1 to entry: It is expressed as a proportion.

3.6

acceptance quality limit

AQL

worst tolerable process fraction nonconforming (3.5) when a continuing series of lots is submitted for acceptance sampling (3.3)

Note 1 to entry: See Clause 5.

3.7

quality level

quality expressed as a rate of occurrence of nonconforming items

3.8

consumer’s risk quality

CRQ

quality level (3.7) of a process which, in the acceptance sampling plan, corresponds to a specified consumer’s risk

Note 1 to entry: In this part of ISO 3951, the quality level (3.7) is the process fraction nonconforming.

Note 2 to entry: In this part of ISO 3951, the consumer’s risk quality corresponds to a consumer’s risk of 10 %.

3.9

producer’s risk

PR

probability of non-acceptance when the quality level has a value stated by the plan as acceptable

Note 1 to entry: Quality level relates to the process fraction nonconforming (3.5) and acceptable relates to the acceptance quality limit (3.6) .

3.10

nonconformity

non-fulfilment of a requirement

3.11

nonconforming unit

unit with one or more nonconformities

[SOURCE:ISO 3534‑2]

3.12

s -method acceptance sampling plan

acceptance sampling (3.3) plan by variables using the sample standard deviation(s)

[SOURCE:ISO 3534‑2]

Note 1 to entry: See Clause 15.

3.13

σ-method acceptance sampling plan

acceptance sampling (3.3) plan by variables using the presumed value(s) of the process standard deviation(s)

[SOURCE:ISO 3534‑2]

Note 1 to entry: See Clause 16.

3.14

specification limit

conformance boundary specified for a characteristic

[SOURCE:ISO 3534‑2]

3.15

lower specification limit

L

specification limit (3.14) that defines the lower conformance boundary

[SOURCE:ISO 3534‑2]

3.16

upper specification limit

U

specification limit (3.14) that defines the upper conformance boundary

[SOURCE:ISO 3534‑2]

3.17

combined control

requirement when nonconformance beyond both the lower specification limit (3.15) and the upper specification limit (3.16) of a quality characteristic belongs to the same class, to which a single AQL (3.6) applies

Note 1 to entry: See 5.3, 16.3.2, 18.3.

Note 2 to entry: The use of a combined acceptance quality limit (3.6) requirement implies that nonconformance beyond either specification limit (3.14) is believed to be of equal, or at least roughly equal, importance to the lack of integrity of the product.

3.18

separate control

requirement when nonconformance beyond the lower specification limit (3.15) and the upper specification limit (3.16) of a quality characteristic belong to different classes, to which separate acceptance quality limits (3.6) are applied

Note 1 to entry: See 5.3, 16.3.3, 17.2.

3.19

complex control

requirement when nonconformance beyond the lower specification limit (3.15) and the upper specification limit (3.16) of a quality characteristic belongs to one class and nonconformance beyond either the upper specification limit (3.16) or the lower specification limit (3.15) belongs to a different class, with separate acceptance quality limits (3.6) being applied to the two classes

Note 1 to entry: See 5.3, 16.3.4, 18.3.

3.20

acceptability constant

k, p*

constant depending on the specified value of the acceptance quality limit (3.6) and the sample size, used in the criteria for accepting the lot in an acceptance sampling (3.3) plan by variables

[SOURCE:ISO 3534‑2]

Note 1 to entry: See 16.2 and 16.3.

3.21

quality statistic

Q

function of the specification limit (3.14) , the sample mean, and the sample or process standard deviation used in assessing the acceptability of a lot

[SOURCE:ISO 3534‑2]

Note 1 to entry: For the case of a single specification limit (3.14) , the lot may be sentenced on the result of comparing Q with the acceptability constant (3.20) k.

Note 2 to entry: See 16.2 and 16.3.

3.22

lower quality statistic

Q_L

function of the lower specification limit (3.15) , the sample mean, and the sample or process standard deviation

Note 1 to entry: For a single lower specification limit (3.15) , the lot is sentenced on the result of comparing Q_L with the acceptability constant (3.20) k.

Note 2 to entry: [SOURCE: ISO 3534-2].

Note 3 to entry: See Clause 4, 16.2 and 16.3.

3.23

upper quality statistic

Q_U

function of the upper specification limit (3.16) , the sample mean, and the sample or process standard deviation

Note 1 to entry: For a single upper specification limit (3.16) , the lot is sentenced on the result of comparing Q_U with the acceptability constant (3.20) k.

Note 2 to entry: [SOURCE: ISO 3534-2].

Note 3 to entry: See Clause 4, 16.2, and 18.3.

3.24

maximum sample standard deviation

MSSD

s_max

largest sample standard deviation for a given sample size code letter and acceptance quality limit (3.6) for which it is possible to satisfy the acceptance criterion for double specification limits (3.14) with a combined acceptance quality limit (3.6) requirement and unknown process variability

[SOURCE:ISO 3534‑2]

Note 1 to entry: See 16.3.2.1 and Annex F.

3.25

maximum process standard deviation

MPSD

σ_max

largest process standard deviation for a given sample size code letter and acceptance quality limit (3.6) for which it is possible to satisfy the acceptance criterion for double specification limits (3.14) with a combined acceptance quality limit (3.6) requirement under tightened inspection with known process variability

[SOURCE:ISO 3534‑2]

Note 1 to entry: See 17.2, 17.3.

3.26

switching rule

instruction within an acceptance sampling (3.3) scheme for changing from one acceptance sampling (3.3) plan to another of greater or lesser severity based on demonstrated quality history

[SOURCE:ISO 3534‑2]

Note 1 to entry: See Clause 23.

Note 2 to entry: Normal, tightened, or reduced inspection or discontinuation of inspection are examples of greater or lesser severity.

3.27

measurement

set of operations to determine the value of some quantity

[SOURCE:ISO 3534‑2]