ASTM E3159-21

Standard Guide for General Reliability

ABSTRACT
This guide covers fundamental concepts, applications, and mathematical relationships associated with reliability as used in industrial areas and as applied to simple components, processes, and systems or complex final products. This guide summarizes selected concepts, terminology, formulas, and methods associated with reliability and its application to products and processes.
SIGNIFICANCE AND USE
4.1 The theory of reliability is used for estimating and demonstrating the probability of survival at specific times or for specific usage cycles for simple components, devices, assemblies, processes, and systems. As reliability is one key dimension of quality, it may be more generally used as a measure of quality over time or over a usage or demand sequence.  
4.1.1 Many industries require performance metrics and requirements that are reliability-centered. Reliability assessments may be needed for the determination of maintenance requirements, for spare parts allocation, for life cycle cost analysis and for warranty purposes. This guide summarizes selected concepts, terminology, formulas, and methods associated with reliability and its application to products and processes. Many mathematical relationships and methods are found in the annexes. For general statistical terms not found in Section 3, Terminology E456 and ISO 3534-1 can be used for definitional purposes and ISO Guide 73 for general terminology regarding risk analysis.  
4.2 The term “system” implies a configuration of interacting components, sub-assemblies, materials, and possibly processes all acting together to make the system work as a whole. Parts of the system may be linked in combinations of series and parallel configuration and redundancy used in some parts to improve reliability. Additional conditions of complex engineering may have to be considered.  
4.3 Process reliability concerns the assessment of any type of well-defined process. This can include manufacturing processes, business processes, and dispatch/demand type processes. Assessment typically measures the extent to which the process can continually perform its intended function without “upset” as well as process robustness.  
4.4 A number of reliability metrics are in use. For example, mean time to failure (MTTF) is a common measure of average life or average time to the first time a unit fails. For this reason it is said to apply t...
SCOPE
1.1 This guide covers fundamental concepts, applications, and mathematical relationships associated with reliability as used in industrial areas and as applied to simple components, processes, and systems or complex final products.  
1.2 The system of units for this guide is not specified. Quantities in the guide are presented only as illustrations of the method or of a calculation. Any examples used are not binding on any particular product or industry.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Apr-2021
• ICS: 21.020 - Characteristics and design of machines, apparatus, equipment
• Technical Committee: E11 - Quality and Statistics
• Drafting Committee: E11.40 - Reliability

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E3159 − 21 An American National Standard
Standard Guide for
1
General Reliability
This standard is issued under the fixed designation E3159; 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.
3
1. Scope 2.2 ISO Standards:
ISO 3534-1 Statistics–Vocabulary and Symbols, Part 1:
1.1 This guide covers fundamental concepts, applications,
Probability and General Statistical Terms
and mathematical relationships associated with reliability as
ISO Guide 73 Risk Management Vocabulary
used in industrial areas and as applied to simple components,
processes, and systems or complex final products.
3. Terminology
1.2 The system of units for this guide is not specified.
3.1 Definitions:
Quantities in the guide are presented only as illustrations of the 3.1.1 Unless otherwise noted, terms relating to quality and
method or of a calculation.Any examples used are not binding statistics are as defined in Terminology E456. Other general
statistical terms and terms related to risk are defined in
on any particular product or industry.
ISO 3534-1 and ISO Guide 73.
1.3 This standard does not purport to address all of the
3.1.2 B life, n—for continuous variables, the life at which
p
safety concerns, if any, associated with its use. It is the
there is a probability, p, (expressed as a percentage) of failure
responsibility of the user of this standard to establish appro-
at or less than this value.
priate safety, health, and environmental practices and deter-
3.1.2.1 Discussion—Example:The B life is a value of life,
10
mine the applicability of regulatory limitations prior to use.
t,suchthatcumulativedistributionfunction,F(t)=0.1or10%.
1.4 This international standard was developed in accor-
3.1.3 failure mode, n—thewayinwhichadevice,processor
dance with internationally recognized principles on standard-
system has failed.
ization established in the Decision on Principles for the
3.1.3.1 Discussion—Under some set of conditions, any
Development of International Standards, Guides and Recom-
device, process or system may be vulnerable to several failure
mendations issued by the World Trade Organization Technical
modes. For example, a tire may fail in the course of time due
Barriers to Trade (TBT) Committee.
to a puncture by a sharp object, from the tire simply wearing
out, or from a tire manufacturing anomaly. Each of these
2. Referenced Documents
describe different failure modes. These three failure modes are
2
said to be competing with respect to the failure event.
2.1 ASTM Standards:
E456 Terminology Relating to Quality and Statistics
3.1.4 hazard rate, n—differential fraction of items failing at
E2334 Practice for Setting an Upper Confidence Bound for a
time t among those surviving up to time t, symbolized by h(t).
Fraction or Number of Non-Conforming items, or a Rate
E2555
of Occurrence for Non-Conformities, Using Attribute
3.1.4.1 Discussion—h(t) is also referred to as the instanta-
Data, When There is a Zero Response in the Sample
neous failure rate at time t and called a hazard function. It is
E2555 Practice for Factors and Procedures for Applying the
related to the probability density (pdf) and cumulative distri-
MIL-STD-105 Plans in Life and Reliability Inspection
bution function (cdf)by h(t) = f(t)/(l – F(t)), where f(t) is the
E2696 Practice for Life and Reliability Testing Based on the
pdf and F(t) the cdf.
Exponential Distribution
3.1.5 mean time between failures (MTBF), n—the average
time to failure for a repairable item.
3.1.5.1 Discussion—A repairable system is one that can be
1
This guide is under the jurisdiction of ASTM Committee E11 on Quality and repaired and returned to service following a failure. When an
Statistics and is the direct responsibility of Subcommittee E11.40 on Reliability.
itemisrepaired,itmaynotnecessarilybereturnedtoservicein
CurrenteditionapprovedMay1,2021.PublishedJuly2021.Originallyapproved
as good as new condition. There may be a reduction in life in
in 2018. Last previous edition approved in 2018 as E3159 – 18. DOI: 10.1520/
a repaired item making the item not as robust as a new item.
E3159-21.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
3
Standards volume information, refer to the standard’s Document Summary page on Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
the ASTM website. 4th Floor, New Y
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E3159 − 18 E3159 − 21 An American National Standard
Standard Guide for
1
General Reliability
This standard is issued under the fixed designation E3159; 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
1.1 This guide covers fundamental concepts, applications, and mathematical relationships associated with reliability as used in
industrial areas and as applied to simple components, processes, and systems or complex final products.
1.2 The system of units for this guide is not specified. Quantities in the guide are presented only as illustrations of the method
or of a calculation. Any examples used are not binding on any particular product or industry.
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, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2
2.1 ASTM Standards:
E456 Terminology Relating to Quality and Statistics
E2334 Practice for Setting an Upper Confidence Bound for a Fraction or Number of Non-Conforming items, or a Rate of
Occurrence for Non-Conformities, Using Attribute Data, When There is a Zero Response in the Sample
E2555 Practice for Factors and Procedures for Applying the MIL-STD-105 Plans in Life and Reliability Inspection
E2696 Practice for Life and Reliability Testing Based on the Exponential Distribution
3
2.2 ISO Standards:
ISO 3534-1 Statistics–Vocabulary and Symbols, Part 1: Probability and General Statistical Terms
ISO Guide 73 Risk Management Vocabulary
3. Terminology
3.1 Definitions:
3.1.1 Unless otherwise noted, terms relating to quality and statistics are as defined in Terminology E456. Other general statistical
terms and terms related to risk are defined in ISO 3534-1 ISO 3534-1 and ISO Guide 73.
1
This guide is under the jurisdiction of ASTM Committee E11 on Quality and Statistics and is the direct responsibility of Subcommittee E11.40 on Reliability.
Current edition approved April 1, 2018May 1, 2021. Published May 2018July 2021. Originally approved in 2018. Last previous edition approved in 2018 as E3159 – 18.
DOI: 10.1520/E3159-18.10.1520/E3159-21.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
3
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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E3159 − 21
3.1.2 B life, n—for continuous variables, the life at which there is a probability, p, (expressed as a percentage) of failure at or
p
less than this value.
3.1.2.1 Discussion—
Example: The B life is a value of life, t, such that cumulative distribution function, F(t) = 0.1 or 10 %.
10
3.1.3 failure mode, n—the way in which a device, process or system has failed.
3.1.3.1 Discussion—
Under some set of conditions, any device, process or system may be vulnerable to several failure modes. For example, a tire may
fail in the course of time due to a puncture by a sharp object, from the tire simply wearing out, or from a tire manufacturing
anomaly. Each of these describe different failure modes. These three failure modes are said to be competing with respect to the
failure event.
3.1.4 hazard rate, n—differential fraction of items failing at time t among those surviving up to time t, symbolized by h(t). E2555
3.1.4.1 Discussion—
h(t) is also referred to as the instantaneous failure rate at time t and called a hazard function. It is related to the probability density
(pdf) and cumulative distribution function (cdf) by h(t) = f(t)/(l – F(t)), where f(t
...