ISO 39511:2018 不適合率（既知の標準偏差）の変数による検査のための順次サンプリング計画 | ページ 6

3.1

inspection by variables

inspection by measuring the magnitude(s) of the characteristic(s) of an item

[SOURCE:ISO 3534‑2:2006, definition 4.1.4]

3.2

sampling inspection

inspection of selected items in the group under consideration

[SOURCE:ISO 3534‑2:2006, definition 4.1.6]

3.3

acceptance sampling

sampling after which decisions are made to accept or not to accept a lot, or other grouping of products, materials or services, based on sample results

[SOURCE:ISO 3534‑2:2006, definition 1.3.17]

3.4

acceptance sampling inspection

acceptance inspection where the acceptability is determined by means of sampling inspection

[SOURCE:ISO 3534‑2:2006, definition 4.1.8]

3.5

acceptance sampling inspection by variables

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

[SOURCE:ISO 3534‑2:2006, definition 4.2.11]

3.6

quality level

quality expressed as a rate of occurrence of nonconforming units

3.7

nonconformity

non-fulfilment of a requirement

[SOURCE:ISO 9000:2015, definition 3.6.9, and ISO 3534‑2:2006, definition 3.1.11]

3.8

nonconforming unit

unit with one or more nonconformities

[SOURCE:ISO 3534‑2:2006, definition 1.2.15]

3.9

specification limit

limiting value stated for a characteristic

[SOURCE:ISO 3534‑2:2006, definition 3.1.3]

3.10

lower specification limit

L

specification limit that defines the lower limiting value

[SOURCE:ISO 3534‑2:2006, definition 3.1.5]

3.11

upper specification limit

U

specification limit that defines the upper limiting value

[SOURCE:ISO 3534‑2:2006, definition 3.1.4]

3.12

combined control

requirement when both upper and lower limits are specified for the quality characteristic and specified risks apply to the combined percent nonconforming beyond the two limits

Note 1 to entry: The use of combined control implies that nonconformities beyond either specification limit are believed to be of equal, or at least roughly equal, importance to the lack of integrity of the product.

3.13

separate control

requirement when both upper and lower limits are specified for the quality characteristic and separate risks are given which apply to each limit

Note 1 to entry: The use of separate control implies that nonconformities beyond either specification limit are believed to be of different importance to the lack of integrity of the product.

3.14

maximum process standard deviation

σ_max

largest process standard deviation for a given sampling plan for which it is possible to satisfy the acceptance criteria for a combined double specification limit when the process variability is known

Note 1 to entry: Maximum process standard deviation σ_max was denoted by its acronym MPSD in older standards.

Note 2 to entry: This definition is different from the similar definition given in ISO 3534-2 in which the concept of AQL is used.

3.15

measurement

set of operations having the object of determining a value of a quantity

[SOURCE:ISO 3534‑2:2006, definition 3.2.1]

3.16

leeway

quantity derived from a measured value of an item

Note 1 to entry: In the case of a single lower specification limit and in the case of double specification limits, the leeway is obtained by subtracting the numerical value of the lower specification limit from the measured value. In the case of an upper specification limit, the leeway is obtained by subtracting the measured value from the numerical value of the upper specification limit.

3.17

cumulative leeway

value calculated by summing the leeways obtained from the start of the inspection up to, and including, that of the item last inspected

3.18

cumulative sample size

total number of inspected items, counting from the start of the inspection up to, and including, the item last inspected

3.19

acceptance value for sequential sampling

value derived from the specified parameters of the sampling plan and the cumulative sample size

Note 1 to entry: Whether the lot may yet be accepted is determined by comparing the cumulative leeway with the acceptance value.

3.20

rejection value for sequential sampling

value derived from the specified parameters of the sampling plan and the cumulative sample size

Note 1 to entry: Whether the lot may yet be considered unacceptable is determined by comparing the cumulative leeway with the rejection value.

3.21

consumer's risk quality

CRQ

Q_cr

<acceptance sampling> quality level of a lot or process which, in the acceptance sampling plan, corresponds to a specified consumer's risk

Note 1 to entry: The specified consumer's risk is usually 10 %.

[SOURCE:ISO 3534‑2:2006, definition 4.6.9]

3.22

producer's risk quality

PRQ

Q_PR

<acceptance sampling> quality level of a lot or process which, in the acceptance sampling plan, corresponds to a specified producer's risk

[SOURCE:ISO 3534‑2:2006, definition 4.6.10]

Note 1 to entry: The specified producer's risk is usually 5 %.

3.23

average sample size

ASSI

<acceptance sampling> average number of units in a sample inspected per lot in reaching decisions to accept or not to accept when using a given acceptance sampling plan

[SOURCE:ISO 3534‑2:2006, definition 4.7.3]

3.24

sequential acceptance sampling inspection

acceptance sampling inspection in which, after each item has been inspected, the decision to accept the lot, not accept the lot, or to inspect another item is taken based on the cumulative sampling evidence to date

[SOURCE:ISO 3534‑2:2006, definition 4.2.7]

3.25

sequential sampling plan

plan which states acceptance criteria in sequential acceptance sampling inspection

3.26

operating characteristic curve

curve showing the relationship between probability of acceptance of product and the incoming quality level for a given acceptance sampling plan

[SOURCE:ISO 3534‑2:2006, definition 4.5.1]

3.27

producer’s risk point

PRP

<acceptance sampling> point on the operating characteristic curve corresponding to a predetermined high probability of acceptance

[SOURCE:ISO 3534‑2:2006, definition 4.6.7]

3.28

consumer’s risk point

CRP

<acceptance sampling> point on the operating characteristic curve corresponding to a predetermined low probability of acceptance

[SOURCE:ISO 3534‑2:2006, definition 4.6.5]