ASTM E2819-11
(Practice)Standard Practice for Single- and Multi-Level Continuous Sampling of a Stream of Product by Attributes Indexed by AQL
Standard Practice for Single- and Multi-Level Continuous Sampling of a Stream of Product by Attributes Indexed by AQL
SIGNIFICANCE AND USE
The reason for preserving military sampling standards is that many organizations throughout the world still use these standards in their current form. MIL-STD-1235B is no longer supported by the U.S. Department of Defense as of the mid-1990s and is out of print, but does exist in the public domain. This practice represents a conversion of MIL-STD-1235B to an ASTM-supported standard.
This practice provides the tables and procedures for applying five different types of continuous sampling plans for inspection by attributes. These continuous sampling plans are discussed in Sections 6-10 of this practice and each section includes information on:
(a) Initiation of 100 % inspection in use.
(b) Requirements on when to switch to sampling inspection.
(c) Conditions warranting a return to 100 % inspection.
(d) When a change in Code Letter, if desired, can be made.
(e) What to do when the checking inspector finds a defect that was originally found conforming by the screening inspector(s), that is, ineffective screening.
(f) Situations where a defect is found before the switch to 100 % inspection causing excessive periods of 100 % inspection so action must be taken, that is, long periods of screening.
Section 6 (Section 2 in MIL-STD-1235B) describes specific procedures and applications of the CSP-1 sampling plansa single-level continuous sampling procedure which provides for alternating between sequences of 100 % inspection and sampling inspection.
Section 7 (Section 3 in MIL-STD-1235B) describes specific procedures and applications of the CSP-F sampling plansa variation of the CSP-1 plans in that CSP-F plans are applied to a relatively short run of product, thereby permitting smaller clearance numbers to be used.
Section 8 (Section 4 in MIL-STD-1235B) describes specific procedures and applications of the CSP-2 sampling plansa modification of CSP-1 in that 100 % inspection resumes only after a prescribed number of defect-free units separate any two defective...
SCOPE
1.1 This practice establishes tables and procedures for applying five different types of continuous sampling plans for inspection by attributes using MIL-STD-1235B as a basis for sampling a steady stream of lots indexed by AQL.
1.2 This practice provides the sampling plans of MIL-STD-1235B in ASTM format for use by ASTM committees and others. It recognizes the continuing usage of MIL-STD-1235B in industries supported by ASTM. Most of the original text in MIL-STD-1235B is preserved in Sections 6-10 of this practice.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Designation: E2819 − 11 AnAmerican National Standard
Standard Practice for
Single- and Multi-Level Continuous Sampling of a Stream of
Product by Attributes Indexed by AQL
This standard is issued under the fixed designation E2819; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Terminology
3.1 Definitions:
1.1 This practice establishes tables and procedures for
3.1.1 For a more extensive list of terms in E11 standards see
applying five different types of continuous sampling plans for
Terminology E456.
inspection by attributes using MIL-STD-1235B as a basis for
3.1.2 acceptance quality limit (AQL), n—qualitylimitthatis
sampling a steady stream of lots indexed by AQL.
the worst tolerable process average when a continuing series of
1.2 This practice provides the sampling plans of MIL-STD-
lots is submitted for acceptance sampling. E2234
1235B in ASTM format for use by ASTM committees and
3.1.3 average outgoing quality (AOQ), n—the average per-
others. It recognizes the continuing usage of MIL-STD-1235B
cent defective of outgoing product including all accepted lots
in industries supported by ASTM. Most of the original text in
or batches after any defectives found in them are replaced by
MIL-STD-1235B is preserved in Sections 6–10 of this
acceptable units, plus all lots or batches which are not accepted
practice.
after such lots or batches have been effectively 100 % in-
1.3 This standard does not purport to address all of the
spected and all defective units replaced by acceptable units.
safety concerns, if any, associated with its use. It is the
E1994
responsibility of the user of this standard to establish appro-
3.1.4 average outgoing quality limit (AOQL), n—the maxi-
priate safety and health practices and determine the applica-
mum AOQ for a given acceptance sampling plan for all
bility of regulatory limitations prior to use.
possible incoming percentages defective for the process.
E1994
2. Referenced Documents
3.1.5 continuous sampling inspection, n—a method of sam-
2.1 ASTM Standards:
pling a stream of product in order of production where the
E456 Terminology Relating to Quality and Statistics
sampling frequency is adjusted based on ongoing inspection
E1994 Practice for Use of Process Oriented AOQL and
results.
LTPD Sampling Plans
3.1.5.1 Discussion—Only those units of product found by
E2234 Practice for Sampling a Stream of Product by Attri-
the inspector or screening crew to be nonconforming are
butes Indexed by AQL
rejected. The rest of production, uninspected units as well as
2.2 Military Standards: units found to be conforming, is allowed to continue down the
MIL-STD-1235A1 Functional Curves of the Continuous
production line as conforming material.
Sampling Plans
3.1.6 critical defect, n—a defect that judgment and experi-
MIL-STD-1235B Single- and Multi-Level Continuous Sam-
ence indicate would result in hazardous or unsafe conditions
pling for Attributes
for individuals using, maintaining, or depending upon the
product, or a defect that judgment and experience indicate is
likely to prevent performance of the function of a major end
item. E2234
This practice is under the jurisdiction ofASTM Committee E11 on Quality and
Statistics and is the direct responsibility of Subcommittee E11.30 on Statistical
3.1.7 critical defective, n—a unit of product which contains
Quality Control.
one or more critical defects and may also contain major and
Current edition approved May 1, 2011. Published July 2011. DOI: 10.1520/
E2819-11. minor, or both, defects. E2234
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
3.1.8 defect, n—any nonconformance of the unit of product
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
with specified requirements. E2234
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
3.1.9 inspection, n—the process of measuring, examining,
Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,
testing, or otherwise comparing the unit of product with the
Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http://
dodssp.daps.dla.mil. requirements. E2234
Copyright ©ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA19428-2959. United States
E2819 − 11
3.1.10 inspection by attributes, n—inspection whereby ei- 3.2.7.1 Discussion—In the typical case the product moves
ther the unit of product is classified simply as defective or on a conveyor belt or line; however, it may be moved in tote
non-defective, or the number of defects in the unit of product boxes, buggies or other conveyances which are operated
is counted, with respect to a given requirement or set of manually or by mobile materials-handling equipment.
requirements. E2234
3.2.8 multi-level, n—plan consisting of periods of 100 %
3.1.11 major defect, n—a defect, other than critical, that is inspection and of sampling inspection at various rates which
likely to result in failure, or to reduce materially the usability
reflect past inspection results.
of the unit of product for its intended purpose. E2234
3.2.9 one hundred percent (100 %) inspection, n—the in-
3.1.12 major defective, n—a unit of product which contains
spection of every unit of product for the defects concerned
one or more major defects, and may also contain minor defects
listed for an inspection station.
but contains no critical defect. E2234
3.2.9.1 Discussion—The two terms, screening and 100 %
inspection, are used interchangeably in this practice.
3.1.13 minor defect, n—a defect that is not likely to reduce
materially the usability of the unit of product for its intended
3.2.10 production interval, n—a finite period of production,
purpose, or is a departure from established standards having
N items in length.
little bearing on the effective use or operation of the unit.
3.2.10.1 Discussion—The production interval is normally a
E2234
shift;itcanbeadayifitisreasonablycertainthatshiftchanges
3.1.14 minor defective, n—a unit of product which contains do not affect quality of product, but shall not be longer than a
one or more minor defects but contains no critical or major day.
defect. E2234
3.2.11 production interval length, n—N, specified number
3.1.15 process average (in inspection), n—the average per- of units to which CSP-F is to be applied.
cent defective or average number of defects per hundred units
3.2.12 sampling frequency, n—f, desired ratio between the
(whichever is applicable) of product submitted by the supplier
number of units of product randomly selected and inspected at
for original inspection. E2234
an inspection station and the number of unit passing the
3.1.16 unit of product, n—thatwhichisinspectedinorderto
inspection station during periods of sampling inspection.
determine its classification as defective or non-defective or to
3.2.12.1 Discussion—In this practice, each f is expressed as
count the number of defects. It may be a single article, a pair,
a fraction of the form, 1/7, 1/25, 1/50, etc. The procedure used
a set, a length, an area, an operation, a volume, a component of
in selecting the sample units should give each unit of product
an end product, or the end product itself. E2234
presented during periods of sampling inspection an equal
3.1.16.1 Discussion—The unit of product may or may not
chance of being selected and inspected. Also referred to as
be the same as the unit of purchase, supply, production, or
“frequency of sampling”.
shipment.
3.2.13 sampling inspection, n—inspection for the defects
3.2 Definitions of Terms Specific to This Standard:
concerned where the units selected for inspection are selected
3.2.1 checking inspection, n—sampling inspection per-
by sampling.
formed by the supplier on units of product which have already
3.2.14 screening, n—100 % inspection where all defective
been100 %inspectedinordertodeterminetheeffectivenessof
units are removed from the production flow.
the screening crew.
3.2.14.1 Discussion—The two terms, screening and 100 %
3.2.1.1 Discussion—This inspection is performed at the
inspection, are used interchangeably in this practice.
sampling rate f or more often.
3.2.15 single-level, n—planconsistingofalternatingperiods
3.2.2 clearance number, n—i, the number of consecutive
of 100 % inspection and sampling inspection wherein the
conforming, that is, defect-free, units in 100 % inspection
sampling rate is constant.
required prior to qualifying for inspection on a sampling basis.
3.2.3 conforming unit, n—a unit that meets the acceptance
4. Significance and Use
criteria established for the characteristic being considered.
4.1 Thereasonforpreservingmilitarysamplingstandardsis
3.2.4 defects concerned, n—defects being inspected for
that many organizations throughout the world still use these
while using the sampling plan.
standards in their current form. MIL-STD-1235B is no longer
3.2.5 inspection by defect class, n—whenonesamplingplan
supported by the U.S. Department of Defense as of the
is associated with inspection for several kinds of defects
mid-1990s and is out of print, but does exist in the public
collectively and each unit of product inspected is inspected for
domain. This practice represents a conversion of MIL-STD-
each of the defects in the class.
1235B to an ASTM-supported standard.
3.2.6 inspection by individual defect, n—inspection where
4.2 This practice provides the tables and procedures for
one sampling plan is associated with inspection for a single
applying five different types of continuous sampling plans for
defect, or where a sampling plan is applied to each of several
inspection by attributes. These continuous sampling plans are
defects independently.
discussed in Sections6–10 of this practice and each section
3.2.7 moving product, n—inspection where product is flow- includes information on:
ing past the inspection station. (a) Initiation of 100 % inspection in use.
E2819 − 11
(b) Requirements on when to switch to sampling inspec- 5.3.1 Method of Classifying Defects—A classification of
tion. defects is the enumeration of possible defects of the unit of
(c) Conditions warranting a return to 100 % inspection. product classified according to their seriousness. Defects will
(d) When a change in Code Letter, if desired, can be made. normally be grouped into one or more of the following classes;
however, defects may be grouped into other classes, or into
(e) What to do when the checking inspector finds a defect
that was originally found conforming by the screening subclasses within these classes.
5.3.1.1 Critical Defect—A critical defect is a defect that
inspector(s), that is, ineffective screening.
(f) Situations where a defect is found before the switch to judgment and experience indicate is likely to result in hazard-
ous or unsafe conditions for individuals using, maintaining, or
100 % inspection causing excessive periods of 100 % inspec-
depending upon the product; or a defect that judgment and
tion so action must be taken, that is, long periods of screening.
experience indicate is likely to prevent performance of the
4.2.1 Section 6 (Section 2 in MIL-STD-1235B) describes
tactical function of a major end item such as a ship, aircraft,
specific procedures and applications of the CSP-1 sampling
tank,missile,orspacevehicle.Notethatforaspecialprovision
plans—a single-level continuous sampling procedure which
relating to critical defects, see 5.8.2.
provides for alternating between sequences of 100 % inspec-
5.3.1.2 Major Defect—Amajor defect is a defect other than
tion and sampling inspection.
critical that is likely to result in failure or materially reduce the
4.2.2 Section 7 (Section 3 in MIL-STD-1235B) describes
usability of the unit of product for its intended purpose.
specific procedures and applications of the CSP-F sampling
5.3.1.3 Minor Defect—Aminor defect is a defect that is not
plans—a variation of the CSP-1 plans in that CSP-F plans are
likely to reduce materially the usability of the unit of product
applied to a relatively short run of product, thereby permitting
for its intended purpose, or is a departure from established
smaller clearance numbers to be used.
standards having little bearing on the effective use or operation
4.2.3 Section 8 (Section 4 in MIL-STD-1235B) describes
of the unit.
specific procedures and applications of the CSP-2 sampling
5.3.2 Method of Classifying Defectives—A defective is a
plans—a modification of CSP-1 in that 100 % inspection
unit of product which contains one or more defects. Defectives
resumes only after a prescribed number of defect-free units
will usually be classified as follows:
separate any two defective sample units.
5.3.2.1 Critical Defective—Acritical defective contains one
4.2.4 Section 9 (Section 5 in MIL-STD-1235B) describes
or more critical defects and may also contain major and minor,
specific procedures and applications of the CSP-T sampling
or both, defects. Note that for a special provision relating to
plans—a multi-level continuous sampling procedure which
critical defectives, see 5.7.2.
provides for reducing the sampling frequency upon demonstra-
5.3.2.2 Major Defective—Amajor defective contains one or
tion of superior product quality.
more major defects, and may also contain minor defects, but
4.2.5 Section 10 (Section 6 in MIL-STD-1235B) describes
contains no critical defects.
specific procedures and applications of the CSP-V sampling
5.3.2.3 Minor Defective—Aminor defective contains one of
plans—a single-level continuous sampling procedure which is
more minor defects but contains no critical or major defects.
analternativetoCSP-Tinthattheseplansprovideforreducing
the clearance number in good quality situations where reduc-
5.4 Acceptable Quality Level (AQL):
tion of sampling frequency has no economic merit.
5.4.1 Definition—For continuous sampling plans, the AQL
is an index to the plans, and has no other meaning.
5. General Description of Sampling Plans
5.4.2 Use—The AQL, together with the Sample Size Code
Letter, is used for indexing the plans provided herein. The
5.1 This practice establishes continuous sampling plans and
plans are also indexed by theAverage Outgoing Quality Limit
procedures for inspection by attributes. When this practice is
(AOQL).
referenced in a contract, specification, inspection standard or
5.4.3 Limitation—The designation of an AQL shall not
similar document, the provisions of this practice shall govern
imply that the supplier has the right to supply kno
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