ASTM E2782-11e1
(Guide)Standard Guide for Measurement Systems Analysis (MSA)
Standard Guide for Measurement Systems Analysis (MSA)
SIGNIFICANCE AND USE
4.1 Many types of measurements are made routinely in research organizations, business and industry, and government and academic agencies. Typically, data are generated from experimental effort or as observational studies. From such data, management decisions are made that may have wide-reaching social, economic, and political impact. Data and decision making go hand in hand and that is why the quality of any measurement is important—for data originate from a measurement process. This guide presents selected concepts and methods useful for describing and understanding the measurement process. This guide is not intended to be a comprehensive survey of this topic.
4.2 Any measurement result will be said to originate from a measurement process or system. The measurement process will consist of a number of input variables and general conditions that affect the final value of the measurement. The process variables, hardware and software and their properties, and the human effort required to obtain a measurement constitute the measurement process. A measurement process will have several properties that characterize the effect of the several variables and general conditions on the measurement results. It is the properties of the measurement process that are of primary interest in any such study. The term “measurement systems analysis” or MSA study is used to describe the several methods used to characterize the measurement process.Note 1—Sample statistics discussed in this guide are as described in Practice E2586; control chart methodologies are as described in Practice E2587.
SCOPE
1.1 This guide presents terminology, concepts, and selected methods and formulas useful for measurement systems analysis (MSA). Measurement systems analysis may be broadly described as a body of theory and methodology that applies to the non-destructive measurement of the physical properties of manufactured objects.
1.2 Units—The system of units for this guide is not specified. Dimensional quantities in the guide are presented only as illustrations of calculation methods and are not binding on products or test methods treated.
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: E2782 − 11 An American National Standard
Standard Guide for
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Measurement Systems Analysis (MSA)
This standard is issued under the fixed designation E2782; 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.
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ε NOTE—Editorial corrections were made throughout in May 2014.
1. Scope principles, (2) an assigned or certified value, based on experi-
mental work of some national or international organization, or
1.1 This guide presents terminology, concepts, and selected
(3) a consensus or certified value, based on collaborative
methods and formulas useful for measurement systems analy-
experimental work under the auspices of a scientific or
sis (MSA). Measurement systems analysis may be broadly
engineering group. E177
described as a body of theory and methodology that applies to
the non-destructive measurement of the physical properties of 3.1.3 calibration, n—process of establishing a relationship
manufactured objects. between a measurement device and a known standard value(s).
1.2 Units—The system of units for this guide is not speci- 3.1.4 gage, n—device used as part of the measurement
process to obtain a measurement result.
fied. Dimensional quantities in the guide are presented only as
illustrations of calculation methods and are not binding on
3.1.5 measurement process, n—process used to assign a
products or test methods treated.
number to a property of an object or other physical entity.
1.3 This standard does not purport to address all of the
3.1.5.1 Discussion—The term “measurement system” is
safety concerns, if any, associated with its use. It is the
sometimes used in place of measurement process. (See 3.1.7.)
responsibility of the user of this standard to establish appro-
3.1.6 measurement result, n—number assigned to a property
priate safety and health practices and determine the applica-
of an object or other physical entity being measured.
bility of regulatory limitations prior to use.
3.1.6.1 Discussion—Theword“measurement”isusedinthe
same sense as measurement result.
2. Referenced Documents
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3.1.7 measurement system, n—the collection of hardware,
2.1 ASTM Standards:
software, procedures and methods, human effort, environmen-
E177 Practice for Use of the Terms Precision and Bias in
tal conditions, associated devices, and the objects that are
ASTM Test Methods
measured for the purpose of producing a measurement.
E456 Terminology Relating to Quality and Statistics
E2586 Practice for Calculating and Using Basic Statistics
3.1.8 measurement systems analysis (MSA), n—any of a
E2587 Practice for Use of Control Charts in Statistical
number of specialized methods useful for studying a measure-
Process Control
ment system and its properties.
3.2 Definitions of Terms Specific to This Standard:
3. Terminology
3.2.1 appraiser, n—the person who uses a gage or measure-
3.1 Definitions:
ment system.
3.1.1 Unless otherwise noted, terms relating to quality and
3.2.2 discrimination ratio, n—statistical ratio calculated
statistics are defined in Terminology E456.
from the statistics from a gage R&R study that measures the
3.1.2 accepted reference value, n—a value that serves as an
number of 97 % confidence intervals, constructed from gage
agreed-upon reference for comparison, and which is derived
R&R variation, that fit within six standard deviations of true
as: (1) a theoretical or established value, based on scientific
object variation.
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3.2.3 distinct product categories, n—alternate meaning of
This guide is under the jurisdiction of ASTM Committee E11 on Quality and
Statistics and is the direct responsibility of Subcommittee E11.20 on Test Method
the discrimination ratio.
Evaluation and Quality Control.
3.2.4 gage consistency, n—constancy of repeatability vari-
Current edition approved Nov. 15, 2011. Published February 2012. DOI:
10.1520/E2782-11E01.
ance over a period of time.
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For referenced ASTM standards, visit the ASTM website, www.astm.org, or
3.2.4.1 Discussion—Consistency means that the variation
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
within measurements of the same object (or group of objects)
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. under the same conditions by the same appraiser behaves in a
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E2782 − 11
state of statistical control as judged, for example, using a 4.2 Any measurement result will be said to originate from a
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