1、BSI Standards PublicationBS ISO 22514-1:2014Statistical methods in processmanagement Capability andperformancePart 1: General principles and conceptsBS ISO 22514-1:2014 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 22514-1:2014.It supersedes BS ISO 22514-1:20
2、09 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee SS/4, Statistical Process Management.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovis
3、ions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2014. Published by BSI StandardsLimited 2014ISBN 978 0 580 83515 5ICS 03.120.30Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published u
4、nder the authority of theStandards Policy and Strategy Committee on 30 June 2014.Amendments issued since publicationDate Text affectedBS ISO 22514-1:2014 ISO 2014Statistical methods in process management Capability and performance Part 1: General principles and conceptsMthodes statistiques dans la g
5、estion de processus Aptitude et performance Partie 1: Principes et concepts gnrauxINTERNATIONAL STANDARDISO22514-1Second edition2014-06-01Reference numberISO 22514-1:2014(E)BS ISO 22514-1:2014ISO 22514-1:2014(E)ii ISO 2014 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2014All rights reserved.
6、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 t
7、he address below or ISOs member body in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 22514-1:2014ISO 22514-1:2014(E) ISO 2014 All rights reserved iiiCo
8、ntents PageForeword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 13.1 Basic terms . 13.2 Performance, measures, and indices 73.3 Capability, measures, and indices 104 Symbols and abbreviated terms 135 Pre-conditions for application 135.1 Aspects about establishing spe
9、cifications 135.2 Distribution and sample size . 135.3 Materials used in studies . 145.4 Special circumstances 146 Collection of data .146.1 Traceability of data . 146.2 Measurement uncertainty 146.3 Data recording 156.4 Outliers . 157 Performance, capability, and process analysis .157.1 Six differe
10、nt types of performance and capability 157.2 Basic considerations . 167.3 Machine performance 187.4 Process performance and process capability 197.5 Position performance . 197.6 Measurement process capability 207.7 Performance and capability indices 218 Results of use .219 Benefits of use 2210 Limit
11、ations of use .22Bibliography .23BS ISO 22514-1:2014ISO 22514-1:2014(E)ForewordISO (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 techni
12、cal 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 w
13、ith 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
14、 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 ri
15、ghts. 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 t
16、his 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 about ISOs adherence to the WTO principles in the Technical Barriers
17、to Trade (TBT) see the following URL: Foreword - Supplementary informationThe committee responsible for this document is ISO/TC 69, Applications of statistical methods, Subcommittee 4, Applications of statistical methods in process management.This second edition cancels and replaces the first editio
18、n (ISO 22514-1:2009), which has been technically revised.ISO 22514 consists of the following parts, under the general title Statistical methods in process management Capability and performance: Part 1: General principles and concepts Part 2: Process capability and performance of time-dependent proce
19、ss models Part 3: Machine performance studies for measured data on discrete parts Part 4: Process capability estimates and performance measures Technical Report Part 6: Process capability statistics for characteristics following a multivariate normal distribution Part 7: Capability of measurement pr
20、ocesses Part 8: Machine performance of a multi-state production processAn additional part, dealing with process capability statistics for attribute characteristics, is planned.iv ISO 2014 All rights reservedBS ISO 22514-1:2014ISO 22514-1:2014(E)IntroductionThis general introduction to capability tre
21、ats the subjects capability and performance in a general way. To understand fully the concepts, it would be helpful to consult ISO 22514-2, ISO 22514-3, and ISO/TR 22514-4. These documents extend this introductory explanation to more specific uses of the procedures.A process can be either a discrete
22、 process or a continuous process. A discrete process generates a sequence of distinguishable items and a continuous process generates a continuous product (e.g. a lane of paper).The purpose of a process is to manufacture a product or perform a service, which satisfies a set of preset specifications.
23、 The specifications for a process under investigation are defined for one or more characteristics of the product or service. However, in process performance or capability, only one characteristic is considered at a time. The characteristic can either be measurable, countable, or it can be a property
24、. The process is, thus, generating either a discrete or a continuous stochastic process. The discrete process can either be a process of real numbers, a process of natural numbers, or a process telling which event from a set of events has occurred for the individual items. As an example, the set of
25、events for the individual items could be colour acceptable; colour not acceptable.In general, the notation for a discrete stochastic process is Xi, where Xi is the outcome of element no. i in the process. In case the characteristic is a property Xi, it is a value given to each of the events in the s
26、et of events used for characterizing the process. For a discrete process, the index i is normally the number of the item in the generated sequence of items. However, sometimes it might be more convenient to use the time from a fixed point as the index. When the process is continuous, a number of pos
27、sibilities exist for the index depending on the nature of the product. When the product is e.g. a lane of paper, the index could be the length from a starting point or it could be the time from a fixed point.It should be noted that normally a serial correlation exists in a stochastic process.A stoch
28、astic process is either stationary or non-stationary. The stringent definition of a stationary stochastic process will not be given here. However, for a stationary process a distribution exists for Xi, which is independent of i.Stochastic processes that satisfy the specifications are either stationa
29、ry processes or well-defined non-stationary processes (e.g. periodic processes).To evaluate a process, a performance study is performed. In fact, a performance study starts as a theoretical study of all the elements in the process before the process is physically implemented. When the parameters of
30、the various stages in the process have been analysed and redefined, the process is implemented (might be only as a test process).Based on sampling from the implemented process, the numerical part of the performance study of the process is started. A number of questions concerning the process will, b
31、eyond any reasonable doubt, be answered correctly. The most important question to be answered is whether the process is a stationary process, which is stable or predictable for a reasonable period. For the process, it is then important to identify the probability distribution of the process and to o
32、btain estimates of the distribution parameters with a reasonable small variance. Based on this information, the next stage in the performance study would be to map the properties of the characteristics under investigation and decide whether they are acceptable. If the properties cannot be accepted,
33、the parameters of the process itself will be changed in order to obtain a process with acceptable properties.Consider a well-defined and implemented process that has been accepted using a performance study. The next stage for the process would then be to ensure that the parameters of the process and
34、 thus, of the stochastic process do not change, or changes in a predicted way. This is performed by defining a suitable capability study.These studies of performance and capability indices are today more and more used to assess production equipment, a process, or even measurement equipment relative
35、to specification criteria. Different types of studies are used depending on the circumstances. ISO 2014 All rights reserved vBS ISO 22514-1:2014BS ISO 22514-1:2014Statistical methods in process management Capability and performance Part 1: General principles and concepts1 ScopeThis part of ISO 22514
36、 describes the fundamental principles of capability and performance of manufacturing processes. It has been prepared to provide guidance about circumstances where a capability study is demanded or necessary to determine if the output from a manufacturing process or the production equipment (a produc
37、tion machine) is acceptable according to appropriate criteria. Such circumstances are common in quality control when the purpose for the study is part of some kind of production acceptance. These studies can also be used when diagnosis is required concerning a production output or as part of a probl
38、em solving effort. The methods are very versatile and have been applied for many situations.This part of ISO 22514 is applicable to the following: organizations seeking confidence that their product characteristics requirements are fulfilled; organizations seeking confidence from their suppliers tha
39、t their product specifications are and will be satisfied; those internal or external to the organization who audit it for conformity with the product requirements; those internal to the organization who deal with analysing and evaluating the existing production situation to identify areas for proces
40、s improvement.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 (includ
41、ing any amendments) applies.ISO 1101, Geometrical product specifications (GPS) Geometrical tolerancing Tolerances of form, orientation, location and run-outISO 22514-7, Statistical methods in process management Capability and performance Part 7: Capability of measurement processes3 Terms and definit
42、ionsFor the purposes of this document, the following terms and definitions apply.3.1 Basic terms3.1.1requirementneed or expectation that is stated, generally implied, or obligatorySOURCE: ISO 9000:2005, 3.1.2INTERNATIONAL STANDARD ISO 22514-1:2014(E) ISO 2014 All rights reserved 1BS ISO 22514-1:2014
43、ISO 22514-1:2014(E)3.1.2processset of inter-related or interacting activities which transforms inputs into outputsNote 1 to entry: Inputs to a process are generally outputs from other processes.Note 2 to entry: Processes in an organization are generally planned and carried out under controlled condi
44、tions to add value.SOURCE: ISO 3534-2:2006, 2.1.1, modified3.1.3systemset of interrelated or interacting elementsSOURCE: ISO 9000:2005, 3.2.13.1.4productresult of a processNote 1 to entry: Four generic product categories are services (e.g. transport), software (e.g. computer program), hardware (e.g.
45、 engine mechanical part), and processed materials (e.g. lubricant).Many products comprise elements belonging to different generic product categories. What the product is then called depends on the dominant element.Note 2 to entry: In mathematics, the concept of product is limited to the result of mu
46、ltiplication.SOURCE: ISO 3534-2:2006, 1.2.323.1.5characteristicdistinguishing feature (of an item)SOURCE: ISO 9000:2005, 3.5.1, modifiedNote 1 to entry: Item is defined in ISO 3534-2:2006, definition 1.2.11. 3.1.6qualitydegree to which a set of inherent characteristics (3.1.5) of a product (3.1.4) f
47、ulfils requirements (3.1.1) of customers and other interested partiesNote 1 to entry: In ISO 9000:2005, 3.1.1, quality is defined without specification of who defines the requirements.3.1.7product characteristicinherent characteristic (3.1.5) of a product (3.1.2)Note 1 to entry: Product characterist
48、ics can be either quantitative or qualitative.Note 2 to entry: The product characteristic can be multidimensional.2 ISO 2014 All rights reservedBS ISO 22514-1:2014ISO 22514-1:2014(E)3.1.8process characteristicinherent characteristic (3.1.5) of a process (3.1.4)Note 1 to entry: Process characteristic
49、s can be either quantitative or qualitative.Note 2 to entry: The process characteristic can be multidimensional.3.1.9quality characteristicinherent characteristic (3.1.5) of a product (3.1.4), process (3.1.2), or system (3.1.3) related to a requirement (3.1.1)Note 1 to entry: Quality characteristics can be either quantitative or qualitative.Note 2 to entry: The quality characteristic can be multidimensional.Note 3 to entry: Often, there is a strong correlation between a process characteristic and a product cha
