1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58Quality Requirements and Evaluation (SQuaRE) Measurement reference model and guideICS 35.080Softwar
2、e engineering Software product BRITISH STANDARDBS ISO/IEC 25020:2007BS ISO/IEC 25020:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 July 2007 BSI 2007ISBN 978 0 580 54052 3Amendments issued since publicationAmd. No. Date Commentscontr
3、act. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.National forewordThis British Standard was published by BSI. It is the UK implementation of ISO/IEC 25020:2007.The UK participation in its preparation was entrusted
4、 to Technical Committee IST/15, Software and systems engineering.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 Reference numberISO/IEC 25020:2007(E)INTERNATIONAL STANDAR
5、D ISO/IEC25020First edition2007-05-15Software engineering Software productQuality Requirements and Evaluation (SQuaRE) Measurement reference model and guide Ingnierie du logiciel Exigences de qualit du produit logiciel et valuation (SQuaRE) Modle de rfrence de mesure et guide BS ISO/IEC 25020:2007ii
6、 iiiContents Foreword iv Introductionv 1 Scope .1 2 Conformance.1 3 Normative references .1 4 Terms and definitions.2 5 Symbols (and abbreviated terms)4 6 Software Product Quality Measurement .5 6.1 Software product quality measurement reference model (SPQM-RM) .5 6.2 Selecting software quality meas
7、ures.5 6.3 Constructing software quality measures 6 Annex A (informative) Examples of criteria for selecting software quality measures and quality measure elements8 Annex B Assessing measurement validity and reliability .10 Annex C Example format for documenting software quality measures .12 Bibliog
8、raphy.15 (informative)(informative)BS ISO/IEC 25020:2007iv Foreword ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Commission) form the specialized system for worldwide standardization. National bodies that are members of ISO or IEC participate i
9、n the development of International Standards through technical committees established by the respective organization to deal with particular fields of technical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international organizations, governmental and no
10、n-governmental, in liaison with ISO and IEC, also take part in the work. In the field of information technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main
11、 task of the joint technical committee is to prepare International Standards. Draft International Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as an International Standard requires approval by at least 75 % of the national bodies castin
12、g a vote. Attention is drawn to the possibility that some of the elements of this part of ISO/IEC 25020 may be the subject of patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights. ISO/IEC FDIS 25020 is part of the SQuaRE series of standards and was p
13、repared by Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee SC 7, Software and systems engineering. SQuaRE series of standards consists of the following divisions under the general title Software engineering,Software product Quality Requirements and Evaluation (SQuaRE):
14、Quality Management Division (ISO/IEC 2500n), Quality Model Division (ISO/IEC 2501n), Quality Measurement Division (ISO/IEC 2502n), Quality Requirements Division (ISO/IEC 2503n), and Quality Evaluation Division (ISO/IEC 2504n). BS ISO/IEC 25020:2007vIntroduction The general goal of creating the SQuaR
15、E series of International Standards is to move to a logically organized, enriched and unified series covering three complementary processes: requirements specification, measurement and evaluation. The purpose of the SQuaRE series of International Standards is to assist those developing and acquiring
16、 software products with the specification and evaluation of quality requirements. It establishes criteria for the specification of software product quality requirements and their evaluation. It includes a two-part quality model for aligning customer definitions of quality with characteristics of the
17、 software product. In addition, the series defines measures of software product quality characteristics that can be used by developers, acquirers and evaluators. It has to be stressed that the SQuaRE series of International Standards is dedicated to software product quality only. The Quality Managem
18、ent Division of the SQuaRE series deals with software products, and is separate and distinct from the “Quality Management“ of processes which is defined in the ISO 9000 family of International Standards. The major benefits of the SQuaRE series over its predecessor standards include: the coordination
19、 of guidance on software product quality measurement and evaluation, guidance for the specification of software product quality requirements, and harmonization with ISO/IEC 15939 in the form of Quality Measurement Reference model presented in this International Standard. The major differences betwee
20、n the SQuaRE series of International Standards and its predecessors, ISO/IEC 9126 and ISO/IEC 14598, are the: introduction of the new general reference model, introduction of dedicated and detailed guides for each division, introduction of Quality Measure Elements within the Quality Measurement Divi
21、sion, introduction of the Quality Requirements Division, incorporation and revision of the evaluation processes, introduction of guidance for practical use in the form of examples, and co-ordination and harmonization of content with ISO/IEC 15939. SQuaRE consists of the following five divisions: Qua
22、lity Management Division (ISO/IEC 2500n), Quality Model Division (ISO/IEC 2501n), Quality Measurement Division (ISO/IEC 2502n), Quality Requirements Division (ISO/IEC 2503n), and Quality Evaluation Division (ISO/IEC 2504n). SQuaRE provides: terms and definitions, BS ISO/IEC 25020:2007vi reference mo
23、dels, a general guide, individual division guides, and standards for requirements specification, measurement and evaluation purposes. SQuaRE includes International Standards and technical reports for a quality model and measures, as well as on quality requirements and evaluation. SQuaRE replaces cur
24、rent ISO/IEC 9126 series and ISO/IEC 14598 series. This International Standard is intended to be used together with ISO/IEC 25010. It is strongly recommended that users refer to ISO/IEC 2500n, ISO/IEC 2501n, ISO/IEC 2503n, and ISO/IEC 2504n division of International Standards prior to using this Int
25、ernational Standard and the associated measurement technical reports, particularly if the user is not familiar with the use of software measures for requirements specification and product evaluation. These International Standards discuss the planning and use of the software quality measures defined
26、in the ISO/IEC 2502n series on software product quality measurement. ISO/IEC 25010 will provide a model and defines terms for software product quality characteristics and how these characteristics are decomposed into subcharacteristics. It does not describe how any of these subcharacteristics could
27、be measured. The Quality Measurement Division provides information and guidance about how to measure the characteristics and subcharacteristics of a quality model. This International Standard provides a reference model and guide for measuring the quality characteristics defined in ISO/IEC 2501n Qual
28、ity Model Division (Figure 1). The associated standards and technical reports within the Quality Measurement Division describe measures of quality throughout the product life cycle. ISO/IEC 25021 offers quality measure elements that can be used to construct software quality measures. Quality measure
29、 elements are the base and derived measures used to create measures of software product quality characteristics. Quality measure elements may measure a static representation of the software, the behaviour of the software, or the effects of the software when it is used. ISO/IEC 25022, ISO/IEC 25023 a
30、nd ISO/IEC 25024 will describe measures for the characteristics in the quality model. Internal measures characterize software product quality based upon static representations of the software, external measures characterize software product quality based upon the behaviour of the computer-based syst
31、em including the software, and quality in use measures characterize software product quality based upon the effects of using the software in a specific context of use. The measures in these technical reports should not be construed as an exhaustive or required set. Figure 2 depicts the relationship
32、between this International Standard and the technical reports in the Quality Measurement Division. Developers, evaluators, quality managers, acquirers, suppliers, maintainers and other users of software may select measures from these technical reports for the measurement of quality characteristics o
33、f interest. In practice this may be with respect to defining requirements, evaluating software products, quality management and other purposes. Users may also modify the measures or use measures which are not included in those technical reports. BS ISO/IEC 25020:2007viiQuality Model Division2501n Qu
34、alityMeasurement Division2502nQuality Management Division2500nQuality RequirementsDivision2503nQuality Evaluation Division2504nFigure 1 Organization of the SQuaRE series of International Standards 25023Measurement of external quality25020Measurement reference model and guide25021Quality measure elem
35、ents25024Measurement of quality in use25022Measurement of internal qualityFigure 2 Structure of the Quality Measurement division BS ISO/IEC 25020:2007blank1Software engineering Software product Quality Requirements and Evaluation (SQuaRE) Measurement reference model and guide 1 Scope The scope of th
36、is International Standard is the selection and construction of software product quality measures, with respect to their use in conjunction with the other SQuaRE series documents. This International Standard also contains the following informative annexes (A through C) and Bibliography: Criteria for
37、selecting software quality measures and quality measure elements Demonstrating predictive validity and assessing measurement reliability Example format for documenting software quality measures Bibliography The SQuaRE series of International Standards is intended for, but not limited to, developers,
38、 acquirers and independent evaluators of software, particularly those responsible for defining software product quality requirements and for software product evaluation. It is recommended that users of SQuaRE use this International Standard as a guide to execute their software product quality measur
39、ement tasks. 2 Conformance Any software product quality measurement that conforms to this International Standard shall fulfil the requirements of Clause 6. 3 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the
40、 edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO/IEC 25000, Software Engineering Software product Quality Requirements and Evaluation (SQuaRE) Guide to SQuaRE ISO/IEC 15939:2002, Software engineering Software measur
41、ement process BS ISO/IEC 25020:20072 4 Terms and definitions For the purposes of this standard, the terms and definitions given in ISO/IEC 25000 and ISO/IEC 15939 apply. The following definitions are replicated here for the convenience of the user of this Internationl Standard. Unattributed referenc
42、es are from ISO/IEC 25000. 4.1 attribute inherent property or characteristic of an entity that can be distinguished quantitatively or qualitatively by human or automated meansISO/IEC 15939:2002 NOTE ISO 9000 distinguishes two types of attributes: a permanent characteristic existing inherently in som
43、ething; and an assigned characteristic of a product, process or system (e.g. the price of a product, the owner of a product). The assigned characteristic is not an inherent quality characteristic of that product, process or system. 4.2 base measure measure defined in terms of an attribute and the me
44、thod for quantifying it NOTE A base measure is functionally independent of other measures. ISO/IEC 15939: 2002, based on the definition in International Vocabulary of Basic and General Terms in Metrology, 1993 4.3 derived measure measure that is defined as a function of two or more values of base me
45、asures ISO/IEC 15939:2002, based on the definition in International Vocabulary of Basic and General Terms in Metrology, 1993 NOTE A transformation of a base measure using a mathematical function can also be considered as a derived measure. 4.4 external software quality capability of a software produ
46、ct to enable the behaviour of a system to satisfy stated and implied needs when the system is used under specified conditions NOTE Attributes of the behaviour can be verified and/or validated by executing the software product during testing and operation. EXAMPLE The number of failures found during
47、testing is an external software quality measure related to the number of faults present in the program. The two measures are not necessarily identical since testing may not find all faults, and a fault may give rise to apparently different failures in different circumstances. 4.5 indicator measure t
48、hat provides an estimate or evaluation of specified attributes derived from a model with respect to defined information needs ISO/IEC 15939:2002 NOTE In ISO/IEC 14598 this definition was, “a measure that can be used to estimate or predict another measure.“ BS ISO/IEC 25020:200734.6 information need
49、ISO/IEC 15939:2002 4.7 internal software quality capability of a set of static attributes of a software product to satisfy stated and implied needs when the software product is used under specified conditions NOTE 1 Static attributes include those that relate to the software architecture, structure and its components. NOTE 2 Static attributes can be verified by review, inspection and/or automated tools. EXAMPLE The number of lines of code, complexity measu
