EN ISO 14253-1:2017

Geometrical product specifications (GPS) - Inspection by measurement of workpieces and measuring equipment - Part 1: Decision rules for verifying conformity or nonconformity with specifications (ISO 14253-1:2017)

ISO 14253-1:2017 establishes the rules for verifying the conformity or nonconformity with a given tolerance for a characteristic of a workpiece (or a population of workpieces) or with a given maximum permissible errors for a metrological characteristic of a measuring equipment, including when the measured value falls close to the specification limits, taking measurement uncertainty into account.
ISO 14253-1:2017 applies to specifications defined in general GPS standards (see ISO 14638), i.e. standards prepared by ISO/TC 213, including:
-      workpiece specifications and population specifications (usually given as an upper specification limit or a lower specification limit or both);
-      measuring equipment specifications (usually given as maximum permissible errors).
ISO 14253-1:2017 only applies for characteristics and maximum permissible errors expressed as quantity values.

Geometrische Produktspezifikationen (GPS) - Prüfung von Werkstücken und Messgeräten durch Messen - Teil 1: Entscheidungsregeln für den Nachweis von Konformität oder Nichtkonformität mit Spezifikationen (ISO 14253-1:2017)

Dieses Dokument legt Regeln für die Prüfung der Konformität oder Nichtkonformität mit einer vorgegebenen Toleranz für das Merkmal eines Werkstücks (oder eine Population von Werkstücken) oder mit den Grenzwerten für Messabweichungen für ein messtechnisches Merkmal eines Messmittels, auch wenn sich der Messwert unter Berücksichtigung der Messunsicherheit sehr nahe an einem der Grenzwerte der Spezifikation befindet.
Dieses Dokument gilt für Spezifikationen in allgemeinen GPS-Normen (siehe ISO 14638), die vom ISO/TC 213 erarbeitet wurden, einschließlich:
- Spezifikationen für Werkstücke und für die Population von Werkstücken (üblicherweise als eine obere Spezifikationsgrenze oder eine untere Spezifikationsgrenze oder beides angegeben);
- Spezifikationen für Messgeräte (üblicherweise als maximal zulässige Messabweichungen angegeben).
Dieses Dokument gilt nur für Merkmale und maximal zulässige Messabweichungen, die als Größenwerte angegeben werden.

Spécification géométrique des produits (GPS) - Vérification par la mesure des pièces et des équipements de mesure - Partie 1: Règles de décision pour contrôler la conformité ou la non-conformité à la spécification (ISO 14253-1:2017)

L'ISO 14253-1 :2017 établit les règles permettant de contrôler la conformité ou la non-conformité à une tolérance donnée pour une caractéristique d'une pièce (ou d'une population de pièces) ou à des erreurs maximales tolérées données pour une caractéristique métrologique d'un équipement de mesure, y compris lorsque la valeur mesurée est proche des limites de spécification, en prenant en compte l'incertitude de mesure.
L'ISO 14253-1 :2017 s'applique aux spécifications définies dans les normes générales GPS (voir l'ISO 14638), c'est-à-dire les normes élaborées par l'ISO/TC 213, comprenant:
-      les spécifications de pièces et les spécifications de population (généralement exprimées sous forme de limite de spécification supérieure, ou de limite de spécification inférieure, ou les deux);
-      les spécifications des équipements de mesure (généralement exprimées sous forme d'erreurs maximales tolérées).
L'ISO 14253-1 :2017 s'applique uniquement aux caractéristiques et aux erreurs maximales tolérées exprimées sous forme de valeurs de grandeurs.

Specifikacija geometrijskih veličin izdelka (GPS) - Preverjanje z merjenjem obdelovancev in z merilno opremo - 1. del: Pravila odločanja za potrjevanje skladnosti ali neskladnosti s specifikacijo (ISO 14253-1:2017)

Ta dokument določa pravila za preverjanje skladnosti ali neskladnosti s podano toleranco za značilnost obdelovanca (ali skupine obdelovancev) ali podanimi največjimi dovoljenimi napakami za meroslovne značilnosti opreme za merjenje, vključno s primeri, ko je izmerjena vrednost blizu omejitev iz specifikacije, pri čemer se upošteva merilna negotovost.
Ta dokument se uporablja za specifikacije, opredeljene v splošnih standardih o specifikaciji geometrijskih veličin proizvoda (glej ISO 14638), tj. standardih, ki jih pripravlja ISO/TC 213, vključno s:
– specifikacijami obdelovanca in populacije (običajno podanimi kot zgornja meja, spodnja meja ali oboje),
– specifikacijami merilne opreme (običajno podanimi kot največje dovoljene napake).
Ta dokument se uporablja za lastnosti in največje dovoljene napake, ki so izražene kot količine/vrednosti.

General Information

• Status: Published
• Publication Date: 05-Dec-2017
• Withdrawal Date: 29-Jun-2018
• ICS: 17.040.01 - Linear and angular measurements in general
• ICS: 17.040.30 - Measuring instruments
• ICS: 17.040.40 - Geometrical Product Specification (GPS)
• Technical Committee: CEN/TC 290 - Dimensional and geometrical product specification and verification
• Drafting Committee: CEN/TC 290 - Dimensional and geometrical product specification and verification
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 06-Dec-2017
• Completion Date: 06-Dec-2017
• Ref Project: SIST EN ISO 14253-1:2018 - Geometrical product specifications (GPS) - Inspection by measurement of workpieces and measuring equipment - Part 1: Decision rules for proving conformity or nonconformity with specifications (ISO 14253-1:2017)

Relations

• Replaces: EN ISO 14253-1:2013 - Geometrical product specifications (GPS) - Inspection by measurement of workpieces and measuring equipment - Part 1: Decision rules for proving conformity or nonconformity with specification (ISO 14253-1:2013)
• Effective Date: 13-Dec-2017

Overview

EN ISO 14253-1:2017 (ISO 14253-1:2017) is a Geometrical Product Specifications (GPS) standard that defines decision rules for verifying conformity or nonconformity of workpiece characteristics and measuring equipment characteristics when inspection is performed by measurement. The standard addresses the practical problem that arises when a measured value lies close to a specification limit: measurement uncertainty must be taken into account before declaring a part or instrument conforming or nonconforming.

Key topics and requirements

• Decision rules for conformity/nonconformity: Establishes default acceptance and rejection zones taking measurement uncertainty into account.
• Measurement uncertainty: Requires estimated measurement uncertainty to be included in the verification process (aligned with ISO/IEC Guide 98‑3 and Guide 98‑4 principles).
• Default conformance probability: The third edition replaces the previous k = 2 coverage factor with a default conformance probability of 95%, making the decision risk constant relative to uncertainty and specification intervals.
• Scope of application: Applies to specifications in general GPS standards (ISO/TC 213), including workpiece specifications, population specifications (USL/LSL), and measuring equipment specifications (maximum permissible errors). It applies only to characteristics expressed as quantity values.
• Supplier/customer roles: Provides guidance for how suppliers and customers should agree in advance on methods to resolve borderline measurement outcomes and defines procedures for verifying conformity (supplier) and nonconformity (customer).
• Normative references: Integrates concepts from ISO 3534‑2, ISO 9000, ISO/IEC Guide 98‑3, ISO/IEC Guide 98‑4 and the VIM.

Applications and who uses it

EN ISO 14253-1:2017 is essential for professionals and organizations involved in dimensional metrology and quality assurance:

• Quality engineers and inspection planners: to define inspection procedures and acceptance criteria that incorporate measurement uncertainty.
• Metrology laboratories and calibration labs: to apply standardized decision rules when certifying measuring equipment or reporting conformity.
• Manufacturing suppliers and OEMs: to structure supplier/customer agreements and resolve disputes when measurements are near spec limits.
• Supply chain quality managers and auditors: to ensure consistent conformity assessment and to reduce commercial risk due to measurement ambiguity.

Practical uses include writing inspection work instructions, designing acceptance/rejection zones, formulating contractual inspection clauses, and supporting conformity assessment decisions in production and calibration environments.

Related standards

• ISO 14638 - GPS matrix model / general GPS standards
• ISO 8015 - Fundamental rules of GPS (overarching principles)
• ISO 18391 - Population specification guidance (referenced for population modifier)
• ISO/IEC Guide 98‑3 & 98‑4 - Expression and role of measurement uncertainty in conformity assessment
• ISO 3534‑2, ISO 9000, VIM - Statistical and metrological vocabulary and concepts

Keywords: ISO 14253-1:2017, EN ISO 14253-1, GPS, geometrical product specifications, measurement uncertainty, decision rules, conformity assessment, specification limits, maximum permissible errors.

Standards Content (Sample)

SLOVENSKI STANDARD
01-februar-2018
1DGRPHãþD
SIST EN ISO 14253-1:2014
6SHFLILNDFLMDJHRPHWULMVNLKYHOLþLQL]GHOND*363UHYHUMDQMH]PHUMHQMHP
REGHORYDQFHYLQ]PHULOQRRSUHPRGHO3UDYLODRGORþDQMD]DSRWUMHYDQMH
VNODGQRVWLDOLQHVNODGQRVWLVVSHFLILNDFLMR,62
Geometrical product specifications (GPS) - Inspection by measurement of workpieces
and measuring equipment - Part 1: Decision rules for proving conformity or
nonconformity with specifications (ISO 14253-1:2017)
Geometrische Produktspezifikationen (GPS) - Prüfung von Werkstücken und
Meßgeräten durch Messen - Teil 1: Entscheidungsregeln für den Nachweis von
Konformität oder Nichtkonformität mit Spezifikationen (ISO 14253-1:2017)
Spécification géométrique des produits (GPS) - Vérification par la mesure des pièces et
des équipements de mesure - Partie 1: Règles de décision pour prouver la conformité ou
la non-conformité à la spécification (ISO 14253-1:2017)
Ta slovenski standard je istoveten z: EN ISO 14253-1:2017
ICS:
17.040.30 Merila Measuring instruments
17.040.40 6SHFLILNDFLMDJHRPHWULMVNLK Geometrical Product
YHOLþLQL]GHOND*36 Specification (GPS)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 14253-1
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2017
EUROPÄISCHE NORM
ICS 17.040.40 Supersedes EN ISO 14253-1:2013
English Version
Geometrical product specifications (GPS) - Inspection by
measurement of workpieces and measuring equipment -
Part 1: Decision rules for verifying conformity or
nonconformity with specifications (ISO 14253-1:2017)
Spécification géométrique des produits (GPS) - Geometrische Produktspezifikationen (GPS) - Prüfung
Vérification par la mesure des pièces et des von Werkstücken und Messgeräten durch Messen - Teil
équipements de mesure - Partie 1: Règles de décision 1: Entscheidungsregeln für den Nachweis von
pour contrôler la conformité ou la non-conformité à la Konformität oder Nichtkonformität mit Spezifikationen
spécification (ISO 14253-1:2017) (ISO 14253-1:2017)
This European Standard was approved by CEN on 28 September 2017.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2017 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 14253-1:2017 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 14253-1:2017) has been prepared by Technical Committee ISO/TC 213
"Dimensional and geometrical product specifications and verification" in collaboration with Technical
Committee CEN/TC 290 “Dimensional and geometrical product specification and verification” the
secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by June 2018 and conflicting national standards shall be
withdrawn at the latest by June 2018.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 14253-1:2013.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 14253-1:2017 has been approved by CEN as EN ISO 14253-1:2017 without any
modification.
INTERNATIONAL ISO
STANDARD 14253-1
Third edition
2017-10
Geometrical product specifications
(GPS) — Inspection by measurement
of workpieces and measuring
equipment —
Part 1:
Decision rules for verifying conformity
or nonconformity with specifications
Spécification géométrique des produits (GPS) — Vérification par la
mesure des pièces et des équipements de mesure —
Partie 1: Règles de décision pour contrôler la conformité ou la non-
conformité à la spécification
Reference number
ISO 14253-1:2017(E)
©
ISO 2017
ISO 14253-1:2017(E)
© ISO 2017, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2017 – All rights reserved

ISO 14253-1:2017(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Default decision rules . 7
4.1 General . 7
4.2 Default conformance probability limit .11
4.3 Default nonconformance probability limit .11
5 Verifying conformity and nonconformity with specifications .11
5.1 General .11
5.2 Rule for verifying conformity with specifications .12
5.2.1 General.12
5.2.2 Case of normal PDF and default conformance probability limit .12
5.3 Rule for verifying nonconformity with specifications .14
5.3.1 General.14
5.3.2 Case of normal PDF and default nonconformance probability limit.14
5.4 Uncertainty zone .15
6 Application in a supplier/customer relationship .16
6.1 General .16
6.2 Supplier verifying conformity .16
6.3 Customer verifying nonconformity .17
Annex A (informative) Relation between the third edition and the second edition .18
Annex B (informative) Relation to the GPS matrix model .21
Bibliography .23
ISO 14253-1:2017(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following
URL: www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 213, Dimensional and geometrical product
specifications and verification, in collaboration with Technical Committee CEN/TC 290, Dimensional and
geometrical product specification and verification.
This third edition cancels and replaces the second edition (ISO 14253-1:2013), which has been
technically revised with the following changes:
— The content applies ISO/IEC Guide 98-4 and gives recommendation for simplification by using
intervals representing the underlying probability. As a consequence, the default coverage factor
k = 2 has been replaced with a default conformance probability of 95 %. This makes the risk constant,
regardless of the relationship between the specification interval and the measurement uncertainty.
See Annex A for additional information.
— Some terminology has been updated.
— The explanation for the population specification modifier has been removed and can now be found
in ISO 18391.
A list of all parts in the ISO 14253 series can be found on the ISO website.
iv © ISO 2017 – All rights reserved

ISO 14253-1:2017(E)
Introduction
This document is a geometrical product specifications (GPS) standard and is to be regarded as a general
GPS standard (see ISO 14638). It influences the chain link D of all chains of general GPS standards.
The ISO/GPS Matrix model given in ISO 14638 gives an overview of the ISO/GPS system of which this
document is a part. The fundamental rules of ISO/GPS given in ISO 8015 apply to this document and the
default decision rules given in this document apply in ISO/GPS, unless otherwise indicated.
For more detailed information on the relation of this document to other standards and the GPS matrix
model, see Annex B for additional information.
The estimated measurement uncertainty is to be taken into account when verifying conformity or
nonconformity with specification.
The problem arises when a measured value falls close to the upper or lower specification limit. In this
case, verification of conformity or nonconformity with specifications is not possible: the measurement
uncertainty induces a probability that a true value of the characteristic is out of specification even if the
measured value falls inside the specification zone, or is in specification even if the measured value falls
outside.
Therefore, suppliers and customers should agree in advance in a method to resolve any issues that may
arise. This document explains how to define default acceptance and rejection zones (i.e. decision rules)
for verifying conformity or nonconformity with specifications.
It is not the intention of this document to consider any prior knowledge of the possible values of the
measurand(s), e.g. the variability of the measured objects, which may influence the probability of
making the correct decision on verification [in mathematical terms, an a priori unconstrained maximum
entropy distribution (12) is assumed].
INTERNATIONAL STANDARD ISO 14253-1:2017(E)
Geometrical product specifications (GPS) — Inspection by
measurement of workpieces and measuring equipment —
Part 1:
Decision rules for verifying conformity or nonconformity
with specifications
1 Scope
This document establishes the rules for verifying the conformity or nonconformity with a given
tolerance for a characteristic of a workpiece (or a population of workpieces) or with a given maximum
permissible errors for a metrological characteristic of a measuring equipment, including when the
measured value falls close to the specification limits, taking measurement uncertainty into account.
This document applies to specifications defined in general GPS standards (see ISO 14638), i.e. standards
prepared by ISO/TC 213, including:
— workpiece specifications and population specifications (usually given as an upper specification
limit or a lower specification limit or both);
— measuring equipment specifications (usually given as maximum permissible errors).
This document only applies for characteristics and maximum permissible errors expressed as
quantity values.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 3534-2, Statistics — Vocabulary and symbols — Part 2: Applied statistics
ISO 9000, Quality management systems — Fundamentals and vocabulary
ISO/IEC Guide 98-3, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in
measurement (GUM:1995)
ISO/IEC Guide 98-4, Uncertainty of measurement — Part 4: Role of measurement uncertainty in conformity
assessment
ISO/IEC Guide 99, International vocabulary of metrology — Basic and general concepts and associated
terms (VIM)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 3534-2, ISO 9000,
ISO/IEC Guide 98-3, ISO/IEC Guide 98-4 and ISO/IEC Guide 99 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at http://www.iso.org/obp
ISO 14253-1:2017(E)
— IEC Electropedia: available at http://www.electropedia.org/
NOTE 1 “Probability density function (PDF)” is defined in ISO 3534-1.
NOTE 2 “Specification limit”, “upper specification limit (USL)”, “lower specification limit (LSL)”, “specified
tolerance” and “population” are defined in ISO 3534-2.
NOTE 3 “Maximum permissible measurement error”, “measurement uncertainty”, “standard measurement
uncertainty”, “combined standard measurement uncertainty”, “coverage interval” and “coverage probability” are
defined in ISO/IEC Guide 99.
NOTE 4 “Acceptance limit”, “acceptance interval”, “rejection interval”, “conformance probability” and “guard
band” are defined in ISO/IEC Guide 98-4.
NOTE 5 “Conformity” and “nonconformity” are defined in ISO 9000.
NOTE 6 For the purposes of this document, “characteristic” is used to express either a workpiece
characteristic, a workpiece population characteristic, or a metrological characteristic of measuring equipment.
Because conformity assessment involves measurement, these characteristics are also referred to as measurands.
3.1
specification zone
interval of values, of the workpiece characteristic or population characteristic or the maximum
permissible error (MPE) of a metrological characteristic of a measuring equipment, fulfilling the
specification
Note 1 to entry: A specification refers to or includes drawings, patterns or other relevant documents.
3.2
conformance probability limit
agreed minimum value of conformance probability when verifying conformity
Note 1 to entry: The conformance probability limit effectively sets the criterion for acceptance when verifying
conformity.
Note 2 to entry: A conformance probability limit of p corresponds to a risk of false acceptance less than or equal
to (1 − p).
3.3
default conformance probability limit
conformance probability limit (3.2) set by this document as default
3.4
lower nonconformance probability
probability that a value of a characteristic is below the lower specification limit
Note 1 to entry: A lower nonconformance probability exists only if a lower specification limit exists.
Note 2 to entry: Conformance probability, lower nonconformance probability and upper nonconformance
probability sum up to unity.
3.5
upper nonconformance probability
probability that a value of a characteristic is above the upper specification limit
Note 1 to entry: An upper nonconformance probability exists only if an upper specification limit exists.
Note 2 to entry: Conformance probability, lower nonconformance probability and upper nonconformance
probability sum up to unity.
2 © ISO 2017 – All rights reserved

ISO 14253-1:2017(E)
3.6
nonconformance probability limit
agreed minimum value of either the upper nonconformance probability (3.5) or the lower nonconformance
probability (3.4) when verifying nonconformity
Note 1 to entry: The nonconformance probability limit effectively sets the criterion for rejection when verifying
nonconformity.
Note 2 to entry: A nonconformance probability limit of p implies a risk of false rejection not exceeding (1 − p).
3.7
default nonconformance probability limit
nonconformance probability limit (3.6) set by this document as default
3.8
acceptance zone
set of one or more acceptance intervals
3.9
default acceptance zone
acceptance zone (3.8) based on the default conformance probability limit (3.3)
Note 1 to entry: See Figure 1.
ISO 14253-1:2017(E)
a) Specification defined only by a lower b) Specification defined only by an upper
specification limit specification limit
c) Specification defined by a lower and an upper specification limit
Key
1 specification zone
2 acceptance limits
3 acceptance zone
4 rejection zone
5 guard band g at lower specification limit
LA
6 guard band g at upper specification limit
UA
Y value of characteristic
LSL lower specification limit
USL upper specification limit
NOTE In most cases, the probability density function (PDF) associated with the measured value of the
characteristic is considered to be symmetrical, so that g , g have the same width.
UA LA
Figure 1 — Acceptance zone and rejection zone when verifying conformity
3.10
rejection zone
set of one or more rejection intervals
Note 1 to entry: The rejection zone is the complement to the acceptance zone (3.8).
3.11
default rejection zone
rejection zone (3.10) based on the default nonconformance probability limit (3.7).
Note 1 to entry: See Figure 2.
4 © ISO 2017 – All rights reserved

ISO 14253-1:2017(E)
a) Specification defined only by a lower b) Specification defined only by an upper
specification limit specification limit
c) Specification defined by a lower and an upper specification limit
Key
1 specification zone
2 acceptance limits
3 acceptance zone
4 rejection zone
7 guard band g at lower specification limit
LR
8 guard band g at upper specification limit
UR
Y value of characteristic
LSL lower specification limit
USL upper s
...