1、BS EN ISO 18391:2016Geometrical product specifications (GPS) Population specification(ISO 18391:2016)BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06BS EN ISO 18391:2016 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN ISO 18391:2
2、016.The UK participation in its preparation was entrusted to Technical Committee TDW/4, Technical Product Realization.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contr
3、act. Users are responsible for its correct application. The British Standards Institution 2016.Published by BSI Standards Limited 2016ISBN 978 0 580 80932 3 ICS 17.040.01 Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the au
4、thority of the Standards Policy and Strategy Committee on 30 November 2016.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e dEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 18391 November 2016 ICS 17.040.40 English Version Geometrical product specifications (GPS) - P
5、opulation specification (ISO 18391:2016) Spcification gomtrique des produits (GPS) - Spcification de population (ISO 18391:2016) Geometrische Produktspezifikation (GPS) - Populationsspezifikation (ISO 18391:2016) This European Standard was approved by CEN on 28 August 2016. CEN members are bound to
6、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-CEN
7、ELEC 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 th
8、e 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, Luxemb
9、ourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussel
10、s 2016 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 18391:2016 EBS EN ISO 18391:2016EN ISO 18391:2016 (E) 3 European foreword This document (EN ISO 18391:2016) has been prepared by Technical Committee ISO/TC 213 “Dimensional
11、 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, eith
12、er by publication of an identical text or by endorsement, at the latest by May 2017, and conflicting national standards shall be withdrawn at the latest by May 2017. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENEL
13、EC shall not be held responsible for identifying any or all such patent rights. 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 Republi
14、c, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorse
15、ment notice The text of ISO 18391:2016 has been approved by CEN as EN ISO 18391:2016 without any modification. BS EN ISO 18391:2016ISO 18391:2016(E)Foreword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 14 Rules for establishing a population specification 34.1 General
16、. 34.2 Rules . 34.2.1 Rule 1: Description of a population specification 34.2.2 Rule 2: Description of type of individual GPS specification (univariate or multivariate) . 54.2.3 Rule 3 . 75 Symbol used to specify a population specification . 86 Rules for indicating a population specification 11Annex
17、A (informative) Relation in the GPS matrix model .15Bibliography .16 ISO 2016 All rights reserved iiiContents PageBS EN ISO 18391:2016ISO 18391:2016(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work
18、 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-governmen
19、tal, 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
20、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. www.iso.org/directivesAttention is drawn to the possibility t
21、hat 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
22、declarations received. www.iso.org/patentsAny 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 meaning of ISO specific terms and expressions related to conformity assessment, as well as information abo
23、ut ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT), see the following URL: Foreword - Supplementary informationThe committee responsible for this document is ISO/TC 213, Dimensional and geometrical product specifications and verification.iv ISO 2016 All rights reservedB
24、S EN ISO 18391:2016ISO 18391:2016(E)IntroductionThis International Standard is a Geometrical Product Specification (GPS) standard and is to be regarded as a global GPS standard (see ISO 14638). It influences all chain links of all chains of standards.The ISO/GPS Masterplan given in ISO 14638 gives a
25、n 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 ISO 14253-1 apply to specifications made in accordance with this document, unless otherwise indicated. For more detaile
26、d information on the relationship of this International standard to other standards and to the GPS matrix model, see Annex A.In order to define the permissible interval for a geometrical characteristic, the designer only defines a condition (a unilateral tolerance limit or a bilateral pair of tolera
27、nce limits) for each workpiece, by considering the worst case impact in an assembly.But when the tolerancing is based on a set of hypotheses about the population of the workpieces, one or more additional requirements should be added to verify these hypotheses.NOTE The intent of this International St
28、andard is not to define calculation methods to determine tolerances, but to give the means to express the hypotheses to verify. ISO 2016 All rights reserved vBS EN ISO 18391:2016BS EN ISO 18391:2016Geometrical product specifications (GPS) Population specification1 ScopeThis International Standard de
29、fines rules to establish and to indicate population specifications, which are used to specify conditions on population characteristics, which are established from a set of characteristic values obtained one on each workpiece of a population of workpieces.A population specification (as applied to a p
30、opulation of workpieces considered as a collection and not as individual items) can be seen as a complementary requirement to the individual specification (as applied to each workpiece considered as individual items). Population specifications express the statistical hypotheses used on the populatio
31、n of workpieces.NOTE 1 A population specification is a complement to an individual GPS specification.NOTE 2 This International Standard is not intended to mandate a given tolerancing method or how to calculate tolerance values. Its intent is to specify tools to allow the expression of population spe
32、cifications.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (includin
33、g any amendments) applies.ISO 1101, Geometrical product specifications (GPS) Geometrical tolerancing Tolerances of form, orientation, location and run-outISO 14405-1, Geometrical product specifications (GPS) Dimensional tolerancing Part 1: Linear sizesISO 17450-1, Geometrical product specifications
34、(GPS) General concepts Part 1: Model for geometrical specification and verification3 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 17450-1 and the following apply.3.1population characteristicstatistic defined from the characteristic values, obtained o
35、n the population of workpieces or the population of assembliesNote 1 to entry: Population characteristics are used to consider the population of workpieces.Note 2 to entry: Population characteristics are only statistically meaningful when the values are based upon global individual characteristics,
36、see Example 2.EXAMPLE 1 The arithmetic mean and the standard deviation of a global individual characteristic on the population of workpieces, are population characteristics.INTERNATIONAL STANDARD ISO 18391:2016(E) ISO 2016 All rights reserved 1BS EN ISO 18391:2016ISO 18391:2016(E)EXAMPLE 2 The minim
37、um circumscribed diameter has one unique value for a given cylindrical feature. Therefore a population characteristic based on this individual characteristic value will be statistically meaningful. The two-point diameter for a given cylindrical feature will vary within a range, dependent upon the fo
38、rm deviations of the feature. In this case, one population characteristic for two-point diameter cannot be defined from the population of values. However, it is possible to establish a population characteristic from the maximum two point diameter along the geometric feature, which is a global indivi
39、dual characteristic, together with a population characteristic from the minimum two-point diameter along the geometric feature which is another global individual characteristic.3.2population conditionlimit that applies to the population characteristic valueNote 1 to entry: Population conditions can
40、be used for statistical process control (SPC).EXAMPLE The mean value, null, of the minimum circumscribed diameter of a population of workpieces can be considered as a population characteristic, and required to be less than or equal to 10,1, which is a population condition (see Clause 6).3.3statistic
41、completely specified function of random variablesSOURCE: ISO 3534-1:2006, definition 1.8, modified Notes have not been reproduced.Note 1 to entry: In GPS, the random variables, which are used are in most of cases one-dimensional (scalar). Multi-dimensional (vector) variables also exist.Note 2 to ent
42、ry: For a population or a sample of individual characteristic values, at least one statistic can be applied. In GPS, a statistic can be used on a population of local individual characteristic values taken on one workpiece or, on a population of global individual characteristic values taken on a popu
43、lation of workpieces.EXAMPLE See Table 1. More information can be found in ISO 3534- series.Table 1 Non exhaustive list of population statisticsaDescription of the statistic Mathematical description according to ISO 35341bA) Minimum minimum (X)B) Maximum maximum (X)C) Mean: expected value =EnXXiin()
44、11,or =Eg gX pgxFxX() () () ()ddD) Mean deviation: difference between the mean and the target value ()=E) Standard deviation = VX()F) VarianceVX EXEX() ()=2G) y % distribution quantile of the variable XyX%: PyxXy=%2 ISO 2016 All rights reservedBS EN ISO 18391:2016ISO 18391:2016(E)Description of the
45、statistic Mathematical description according to ISO 35341bH) Median, i.e 50 % distribution quantile50 %XI) Median absolute deviation from medianc50 % with =xX50 %aThe symbols used in this table are defined in Table 2bWhere X is the global characteristic value on one workpiece.cSee Reference 6.4 Rule
46、s for establishing a population specification4.1 GeneralA population characteristic is a characteristic, which is calculated from a set of values, each of which is an global individual characteristic value obtained on one workpiece of the population.In some applications it is necessary to specify th
47、at one or more relations between the workpieces of the population shall be satisfied. The following rules describe the implication on the individual specification, and how to indicate a population specification.A population characteristic can be used to manage statistical tolerancing requirements or
48、 the implementation of statistical process control indexes.4.2 Rules4.2.1 Rule 1: Description of a population specification4.2.1.1 Rule # 1a (indicating a population specification)By default, a GPS specification is an individual specification. When a population specification is required to complemen
49、t an individual specification then the tolerance value of the individual GPS specification shall be followed by the modifier .4.2.1.2 Rule # 1b (individual characteristic)To define a population characteristic, an individual specification shall be used to define an individual signed global characteristic on each workpiece. In cases where the characteristic captures material deviation, the positive direction is out of the material.4.2.1.3 Rule # 1c (deriving a global characteristic from a local
