1、 Reference number ISO/IEC 20926:2009(E) ISO/IEC 2009INTERNATIONAL STANDARD ISO/IEC 20926 Second edition 2009-12-01Software and systems engineering Software measurement IFPUG functional size measurement method 2009 Ingnierie du logiciel et des systmes Mesurage du logiciel Mthode IFPUG 2009 de mesurag
2、e de la taille fonctionnelle ISO/IEC 20926:2009(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer
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5、tral Secretariat at the address given below. COPYRIGHT PROTECTED DOCUMENT ISO/IEC 2009 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permi
6、ssion in writing from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO/IEC 2009 All rights r
7、eservedISO/IEC 20926:2009(E) ISO/IEC 2009 All rights reserved iiiContents Page Foreword iv Introduction.v 1 Scope1 1.1 Purpose 1 1.2 Conformity .1 1.3 Applicability .1 1.4 Audience 1 2 Normative references1 3 Terms and definitions .2 4 Abbreviated terms.8 5 Measurement Process 8 5.1 Overview.8 5.2 G
8、ather the available documentation .9 5.3 Determine the counting scope and boundary and identify Functional User Requirements .9 5.4 Measure data functions 10 5.5 Measure transactional functions .13 5.6 Measure conversion functionality .19 5.7 Measure enhancement functionality .19 5.8 Calculate funct
9、ional size 19 5.9 Document the function point count.21 5.10 Report the result of the function point count.21 Annex A (informative) Consolidated complexity and functional size tables23 Bibliography24 ISO/IEC 20926:2009(E) iv ISO/IEC 2009 All rights reservedForeword ISO (the International Organization
10、 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 in the development of International Standards through technical committees established by the respective
11、 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 non-governmental, in liaison with ISO and IEC, also take part in the work. In the field of information te
12、chnology, 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 task of the joint technical committee is to prepare International Standards. Draft International Stand
13、ards 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 casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the s
14、ubject of patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights. ISO/IEC 20926 was prepared by the International Function Point Users Group (IFPUG) and was adopted, under the PAS procedure, by Joint Technical Committee ISO/IEC JTC 1, Information techn
15、ology, in parallel with its approval by national bodies of ISO and IEC. This second edition cancels and replaces the first edition (ISO/IEC 20926:2003), which has been technically revised. ISO/IEC 20926:2009(E) ISO/IEC 2009 All rights reserved vIntroduction The use of function points, as a measure o
16、f the functional size of software, has grown since the mid 1970s from a few interested organizations to an impressive list of organizations worldwide. Allan Albrecht was the first to publicly release a method for functionally sizing software called function point analysis. With the growth in the use
17、 of function points, there has been wider application and use of the measure. Since its formation in 1986 the International Function Point Users Group (IFPUG) has continuously enhanced the original Albrecht method for functionally sizing software. This International Standard is the latest release in
18、 the continually improving IFPUG method that promotes the consistent interpretation of functional size measurement in conformance with ISO/IEC 14143-1:2007. The IFPUG functional size measurement method is known as function point analysis and its units of functional size are called Function Points. O
19、rganizations can apply this International Standard to measure the size of a software product to: support quality and productivity analysis; estimate cost and resources required for software development, enhancement and maintenance; provide a normalization factor for software comparison; determine th
20、e size of a purchased application package by functionally sizing all the functions included in the package; assist users in determining the benefit of an application package to their organization by functionally sizing functions that specifically match their requirements. Function point analysis mea
21、sures software by quantifying the tasks and services (i.e., functionality) that the software provides to the user based primarily on logical design. The objectives of function point analysis are to measure: functionality implemented in software, that the user requests and receives; functionality imp
22、acted by software development, enhancement and maintenance independently of technology used for implementation. The process of function point analysis is: simple enough to minimize the overhead of the measurement process; a consistent measure among various projects and organizations. In order to eff
23、ectively apply this International Standard, persons can be formally trained in the method using IFPUG certified course materials. This International Standard is one component in the IFPUG publications. It is recommended that it be read in conjunction with the other IFPUG publications. These provide
24、guidance to application of the rules specified within this International Standard and background information to aid in understanding the use and applicability of the resulting functional size. Supporting IFPUG publications include the following: the current version of the IFPUG Counting Practices Ma
25、nual, which incorporates this International Standard supplemented with counting practices and examples that support its implementation; ISO/IEC 20926:2009(E) vi ISO/IEC 2009 All rights reserved “Framework for Functional Sizing”, 2005, which discusses the contribution of both functional size and non-
26、functional size to the overall software product size; the IFPUG FSM method is a method for measuring the functional size; IFPUG website at www.ifpug.org. INTERNATIONAL STANDARD ISO/IEC 20926:2009(E) ISO/IEC 2009 All rights reserved 1Software and systems engineering Software measurement IFPUG functio
27、nal size measurement method 2009 1 Scope 1.1 Purpose This International Standard specifies the set of definitions, rules and steps for applying the IFPUG functional size measurement (FSM) method. 1.2 Conformity This International Standard is conformant with all mandatory provisions of ISO/IEC 14143-
28、1:2007. 1.3 Applicability This International Standard can be applied to all functional domains. NOTE IFPUG continues to publish white papers providing guidelines for use in evolving environments and domains. This International Standard is fully convertible to prior editions of IFPUG sizing methods.
29、IFPUG function point analysts have identified different delivery rates (hours to deliver a function point) related to building applications in different functional domains calibrated for varying project sizes and software complexities. 1.4 Audience This International Standard can be applied by anyon
30、e requiring a measurement of functional size. Persons experienced with the method will find this International Standard to be a useful reference. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition c
31、ited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO/IEC 14143-1:2007, Information technology Software measurement Functional size measurement Part 1: Definition of concepts ISO/IEC 20926:2009(E) 2 ISO/IEC 2009 All rights reserve
32、d3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 adaptive maintenance modification of a software product, performed after delivery, to keep a software product usable in a changed or changing environment NOTE Adaptive maintenance provides enha
33、ncements necessary to accommodate changes in the environment in which a software product must operate. These changes are those that must be made to keep pace with the changing environment. For example, the operating system might be upgraded and some changes may be made to accommodate the new operati
34、ng system. ISO/IEC 14764:2006, 3.1 3.2 application cohesive collection of automated procedures and data supporting a business objective, consisting of one or more components, modules, or subsystems EXAMPLES Accounts payable, accounts receivable, payroll, procurement, shop production, assembly line c
35、ontrol, air search radar, target tracking, weapons firing, flight line scheduling and passenger reservations. 3.3 application functional size measure of the functionality that an application provides to the user, determined by the application function point count 3.4 application function point count
36、 activity of applying this International Standard to measure the functional size of an application 3.5 arranging activity of sequencing attributes in a transactional function 3.6 associative entity type entity type that contains attributes which further describe a many-to-many relationship between t
37、wo other entity types 3.7 attributive entity type entity type that further describes one or more attributes of another entity type 3.8 base functional component BFC elementary unit of Functional User Requirements defined by and used by an FSM Method for measurement purposes EXAMPLE A Functional User
38、 Requirement could be “Maintain Customers”, which might consist of the following BFCs: “Add a new customer”, “Report Customer Purchases”, and “Change Customer Details”. Another example might include a collection of logically related business data maintained by the software under study such as “Custo
39、mer Details”. There are many other examples. ISO/IEC 14143-1:2007, 3.1 ISO/IEC 20926:2009(E) ISO/IEC 2009 All rights reserved 33.9 boundary conceptual interface between the software under study and its users ISO/IEC 14143-1:2007, 3.3 NOTE ISO/IEC 20926:2003 used the term “application boundary”. 3.10
40、 consistent state point at which processing has been fully executed, the Functional User Requirement has been satisfied and there is nothing more to be done EXAMPLE 1 The Functional User Requirement is to print a check and mark the appropriate account as paid. If only part of the Functional User Req
41、uirement is completed (e.g., only printing the check or only marking it as paid), the application is not in a consistent state. The printing of a check without marking the account as paid causes an inconsistency in the application as does marking it as paid without printing it. EXAMPLE 2 The Functio
42、nal User Requirement is to have a batch process that accepts an input file to update a data store, produce a production control report and return an error report back to the sending application. The process is not in a consistent state unless all of these parts are completed. EXAMPLE 3 The Functiona
43、l User Requirement is to transfer an employee to a new job and validate his/her security clearance level. To complete this, a real-time request is sent to the security application (which maintains government security clearances and not application security) and a response received before the transfe
44、r can be completed. All steps are needed to create a consistent state. The interaction with the security application is not an independent step or action. It does not happen in and of itself, and the transaction to transfer an employee is not in a consistent state without it. 3.11 control informatio
45、n data that influences an elementary process by specifying what, when or how data is to be processed 3.12 conversion functionality transactional or data functions provided to convert data and/or provide other user specified conversion requirements NOTE Conversion functionality exists only during the
46、 development or enhancement of an application. 3.13 corrective maintenance reactive modification of a software product performed after delivery to correct discovered problems NOTE The modification repairs the software product to satisfy requirements. ISO/IEC 14764:2006, 3.2 3.14 counting scope set o
47、f Functional User Requirements to be included in the function point count 3.15 Data Element Type DET unique, user recognizable, non-repeated attribute 3.16 data function functionality provided to the user to meet internal or external data storage requirements NOTE A data function is either an Intern
48、al Logical File or an External Interface File. ISO/IEC 20926:2009(E) 4 ISO/IEC 2009 All rights reserved3.17 derived data data created as a result of processing that involves steps other than or in addition to direct retrieval and validation of information from data functions 3.18 development project
49、 project to develop and deliver the first release of a software application 3.19 development project functional size measure of the functionality provided to the users with the first release of the software, as measured by the development project function point count NOTE The functional size of a development project can include the size of conversion functionality. 3.20 development project function point count activity of applying this International Standard to measure the functional size of a deve
