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The Institute of Electrical and Electronics Engineers, Inc. 345 East 47th Street, New York, NY 10017-2394, USA Copyright © 1998 by the Institute of Electrical and Electronics Engineers, Inc. All rights reserved. Published 1998. Printed in the United States of America. ISBN 0-7381-0332-2 No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior written permission of the publisher. IEEE Std 830-1998 (Revision of IEEE Std 830-1993) IEEE Recommended Practice for Software Requirements SpeciÞcations Sponsor Software Engineering Standards Committee of the IEEE Computer Society Approved 25 June 1998 IEEE-SA Standards Board Abstract: The content and qualities of a good software requirements specification (SRS) are de- scribed and several sample SRS outlines are presented. This recommended practice is aimed at specifying requirements of software to be developed but also can be applied to assist in the selec- tion of in-house and commercial software products. Guidelines for compliance with IEEE/EIA 12207.1-1997 are also provided. Keywords: contract, customer, prototyping, software requirements specification, supplier, system requirements specifications IEEE Standards documents are developed within the IEEE Societies and the Standards Coordinat- ing Committees of the IEEE Standards Association (IEEE-SA) Standards Board. Members of the committees serve voluntarily and without compensation. They are not necessarily members of the Institute. The standards developed within IEEE represent a consensus of the broad expertise on the subject within the Institute as well as those activities outside of IEEE that have expressed an inter- est in participating in the development of the standard. Use of an IEEE Standard is wholly voluntary. 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The IEEE shall not be responsible for identifying patents for which a license may be required by an IEEE standard or for conducting inquiries into the legal validity or scope of those patents that are brought to its attention. Copyright © 1998 IEEE. All rights reserved. iii Introduction (This introduction is not a part of IEEE Std 830-1998, IEEE Recommended Practice for Software Requirements SpeciÞ- cations.) This recommended practice describes recommended approaches for the speciÞcation of software require- ments. It is based on a model in which the result of the software requirements speciÞcation process is an unambiguous and complete speciÞcation document. It should help a) Software customers to accurately describe what they wish to obtain; b) Software suppliers to understand exactly what the customer wants; c) Individuals to accomplish the following goals: 1) Develop a standard software requirements speciÞcation (SRS) outline for their own organiza- tions; 2) DeÞne the format and content of their speciÞc software requirements speciÞcations; 3) Develop additional local supporting items such as an SRS quality checklist, or an SRS writerÕs handbook. To the customers, suppliers, and other individuals, a good SRS should provide several speciÞc beneÞts, such as the following: Ñ Establish the basis for agreement between the customers and the suppliers on what the software product is to do. The complete description of the functions to be performed by the software speciÞed in the SRS will assist the potential users to determine if the software speciÞed meets their needs or how the software must be modiÞed to meet their needs. Ñ Reduce the development effort. The preparation of the SRS forces the various concerned groups in the customerÕs organization to consider rigorously all of the requirements before design begins and reduces later redesign, recoding, and retesting. Careful review of the requirements in the SRS can reveal omissions, misunderstandings, and inconsistencies early in the development cycle when these problems are easier to correct. Ñ Provide a basis for estimating costs and schedules. The description of the product to be developed as given in the SRS is a realistic basis for estimating project costs and can be used to obtain approval for bids or price estimates. Ñ Provide a baseline for validation and veriÞcation. Organizations can develop their validation and veriÞcation plans much more productively from a good SRS. As a part of the development contract, the SRS provides a baseline against which compliance can be measured. Ñ Facilitate transfer. The SRS makes it easier to transfer the software product to new users or new machines. Customers thus Þnd it easier to transfer the software to other parts of their organization, and suppliers Þnd it easier to transfer it to new customers. Ñ Serve as a basis for enhancement. Because the SRS discusses the product but not the project that developed it, the SRS serves as a basis for later enhancement of the Þnished product. The SRS may need to be altered, but it does provide a foundation for continued production evaluation. The readers of this document are referred to Annex B for guidelines for using this recommended practice to meet the requirements of IEEE/EIA 12207.1-1997, IEEE/EIA GuideÑIndustry Implementation of ISO/IEC 12207: 1995, Standard for Information TechnologyÑSoftware life cycle processesÑLife cycle data. iv Copyright © 1998 IEEE. All rights reserved. Participants This recommended practice was prepared by the Life Cycle Data Harmonization Working Group of the Soft- ware Engineering Standards Committee of the IEEE Computer Society. At the time this recommended prac- tice was approved, the working group consisted of the following members: Leonard L. Tripp, Chair The following persons were on the balloting committee: Edward Byrne Paul R. Croll Perry DeWeese Robin Fralick Marilyn Ginsberg-Finner John Harauz Mark Henley Dennis Lawrence David Maibor Ray Milovanovic James Moore Timothy Niesen Dennis Rilling Terry Rout Richard Schmidt Norman F. Schneidewind David Schultz Basil Sherlund Peter Voldner Ronald Wade Syed Ali Theodore K. Atchinson Mikhail Auguston Robert E. Barry Leo Beltracchi H. Ronald Berlack Richard E. Biehl Michael A. Blackledge Sandro Bologna Juris Borzovs Kathleen L. Briggs M. Scott Buck Michael Caldwell James E. Cardow Enrico A. Carrara Lawrence Catchpole Keith Chan Antonio M. Cicu Theo Clarke Sylvain Clermont Rosemary Coleman Virgil Lee Cooper W. W. Geoff Cozens Paul R. Croll Gregory T. Daich Geoffrey Darnton Taz Daughtrey Bostjan K. Derganc Perry R. DeWeese James Do Evelyn S. Dow Carl Einar Dragstedt Sherman Eagles Christof Ebert Leo Egan Richard E. Fairley John W. Fendrich Jay Forster Kirby Fortenberry Eva Freund Richard C. Fries Roger U. Fujii Adel N. Ghannam Marilyn Ginsberg-Finner John Garth Glynn Julio Gonzalez-Sanz L. M. Gunther David A. Gustafson Jon D. Hagar John Harauz Robert T. Harley Herbert Hecht William Heßey Manfred Hein Mark Heinrich Mark Henley Debra Herrmann John W. Horch Jerry Huller Peter L. Hung George Jackelen Frank V. Jorgensen William S. Junk George X. Kambic Richard Karcich Ron S. Kenett Judith S. Kerner Robert J. Kierzyk Dwayne L. Knirk Shaye Koenig Thomas M. Kurihara John B. Lane J. Dennis Lawrence Fang Ching Lim William M. Lively James J. Longbucco Dieter Look John Lord Stan Magee David Maibor Harold Mains Robert A. Martin Tomoo Matsubara Mike McAndrew Patrick D. McCray Christopher McMacken Jerome W. Mersky Bret Michael Alan Miller Celia H. Modell James W. Moore Pavol Navrat Myrna L. Olson Indradeb P. Pal Alex Polack Peter T. Poon Lawrence S. Przybylski Kenneth R. Ptack Annette D. Reilly Dennis Rilling Andrew P. Sage Helmut Sandmayr Stephen R. Schach Hans Schaefer Norman Schneidewind David J. Schultz Lisa A. Selmon Robert W. Shillato David M. Siefert Carl A. Singer James M. Sivak Richard S. Sky Nancy M. Smith Melford E. Smyre Harry M. Sneed Alfred R. Sorkowitz Donald W. Sova Luca Spotorno Julia Stesney Fred J. Strauss Christine Brown Strysik Toru Takeshita Richard H. Thayer Booker Thomas Patricia Trellue Theodore J. Urbanowicz Glenn D. Venables Udo Voges David D. Walden Dolores Wallace William M. Walsh John W. Walz Camille SWhite-Partain Scott A. Whitmire P. A. Wolfgang Paul R. Work Natalie C. Yopconka Janusz Zalewski Geraldine Zimmerman Peter F. Zoll Copyright © 1998 IEEE. All rights reserved. v When the IEEE-SA Standards Board approved this recommended practice on 25 June 1998, it had the fol- lowing membership: Richard J. Holleman, Chair Donald N. Heirman, Vice Chair Judith Gorman, Secretary *Member Emeritus Valerie E. Zelenty IEEE Standards Project Editor Satish K. Aggarwal Clyde R. Camp James T. Carlo Gary R. Engmann Harold E. Epstein Jay Forster* Thomas F. Garrity Ruben D. Garzon James H. Gurney Jim D. Isaak Lowell G. Johnson Robert Kennelly E. G. ÒAlÓ Kiener Joseph L. KoepÞnger* Stephen R. Lambert Jim Logothetis Donald C. Loughry L. Bruce McClung Louis-Franois Pau Ronald C. Petersen Gerald H. Peterson John B. Posey Gary S. Robinson Hans E. Weinrich Donald W. Zipse vi Copyright © 1998 IEEE. All rights reserved. Contents 1. Overview.............................................................................................................................................. 1 1.1 Scope............................................................................................................................................ 1 2. References............................................................................................................................................ 2 3. Definitions............................................................................................................................................ 2 4. Considerations for producing a good SRS........................................................................................... 3 4.1 Nature of the SRS ........................................................................................................................ 3 4.2 Environment of the SRS .............................................................................................................. 3 4.3 Characteristics of a good SRS...................................................................................................... 4 4.4 Joint preparation of the SRS ........................................................................................................ 8 4.5 SRS evolution .............................................................................................................................. 8 4.6 Prototyping................................................................................................................................... 9 4.7 Embedding design in the SRS...................................................................................................... 9 4.8 Embedding project requirements in the SRS............................................................................. 10 5. The parts of an SRS ........................................................................................................................... 10 5.1 Introduction (Section 1 of the SRS)........................................................................................... 11 5.2 Overall description (Section 2 of the SRS)................................................................................ 12 5.3 Specific requirements (Section 3 of the SRS)............................................................................ 15 5.4 Supporting information.............................................................................................................. 19 Annex A (informative) SRS templates........................................................................................................ 21 Annex B (informative) Guidelines for compliance with IEEE/EIA 12207.1-1997.................................... 27 Copyright © 1998 IEEE. All rights reserved. 1 IEEE Recommended Practice for Software Requirements SpeciÞcations 1. Overview This recommended practice describes recommended approaches for the speciÞcation of software require- ments. It is divided into Þve clauses. Clause 1 explains the scope of this recommended practice. Clause 2 lists the references made to other standards. Clause 3 provides deÞnitions of speciÞc terms used. Clause 4 provides background information for writing a good SRS. Clause 5 discusses each of the essential parts of an SRS. This recommended practice also has two annexes, one which provides alternate format templates, and one which provides guidelines for compliance with IEEE/EIA 12207.1-1997. 1.1 Scope This is a recommended practice for writing software requirements speciÞcations. It describes the content and qualities of a good software requirements speciÞcation (SRS) and presents several sample SRS outlines. This recommended practice is aimed at specifying requirements of software to be developed but also can be applied to assist in the selection of in-house and commercial software products. However, application to already-developed software could be counterproductive. When software is embedded in some larger system, such as medical equipment, then issues beyond those identiÞed in this recommended practice may have to be addressed. This recommended practice describes the process of creating a product and the content of the product. The product is an SRS. This recommended practice can be used to create such an SRS directly or can be used as a model for a more speciÞc standard. This recommended practice does not identify any speciÞc method, nomenclature, or tool for preparing an SRS. IEEE Std 830-1998 IEEE RECOMMENDED PRACTICE FOR 2 Copyright © 1998 IEEE. All rights reserved. 2. References This recommended practice shall be used in conjunction with the following publications. ASTM E1340-96, Standard Guide for Rapid Prototyping of Computerized Systems. 1 IEEE Std 610.12-1990, IEEE Standard Glossary of Software Engineering Terminology. 2 IEEE Std 730-1998, IEEE Standard for Software Quality Assurance Plans. IEEE Std 730.1-1995, IEEE Guide for Software Quality Assurance Planning. IEEE Std 828-1998, IEEE Standard for Software ConÞguration Management Plans. 3 IEEE Std 982.1-1988, IEEE Standard Dictionary of Measures to Produce Reliable Software. IEEE Std 982.2-1988, IEEE Guide for the Use of IEEE Standard Dictionary of Measures to Produce Reli- able Software. IEEE Std 1002-1987 (Reaff 1992), IEEE Standard Taxonomy for Software Engineering Standards. IEEE Std 1012-1998, IEEE Standard for Software VeriÞcation and Validation. IEEE Std 1012a-1998, IEEE Standard for Software VeriÞcation and Validation: Content Map to IEEE/EIA 12207.1-1997. 4 IEEE Std 1016-1998, IEEE Recommended Practice for Software Design Descriptions. 5 IEEE Std 1028-1997, IEEE Standard for Software Reviews. IEEE Std 1042-1987 (Reaff 1993), IEEE Guide to Software ConÞguration Management. IEEE P1058/D2.1, Draft Standard for Software Project Management Plans, dated 5 August 1998. 6 IEEE Std 1058a-1998, IEEE Standard for Software Project Management Plans: Content Map to IEEE/EIA 12207.1-1997. 7 IEEE Std 1074-1997, IEEE Standard for Developing Software Life Cycle Processes. IEEE Std 1233, 1998 Edition, IEEE Guide for Developing System Requirements SpeciÞcations. 8 1 ASTM publications are available from the American Society for Testing and Materials, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, USA. 2 IEEE publications are available from the Institute of Electrical and Electronics Engineers, 445 Hoes Lane, P.O. Box 1331, Piscataway, NJ 08855-1331, USA. 3 As this standard goes to press, IEEE Std 828-1998; IEEE Std 1012a-1998; IEEE Std 1016-1998; and IEEE Std 1233, 1998 Edition are approved but not yet published. The draft standards are, however, available from the IEEE. Anticipated publication date is Fall 1998. Contact the IEEE Standards Department at 1 (732) 562-3800 for status information. 4 See Footnote 3. 5 See Footnote 3. 6 Upon approval of IEEE P1058 by the IEEE-SA Standards Board, this standard will be integrated with IEEE Std 1058a-1998 and published as IEEE Std 1058, 1998 Edition. Approval is expected 8 December 1998. 7 As this standard goes to press, IEEE Std 1058a-1998 is approved but not yet published. The draft standard is, however, available from the IEEE. Anticipated publication date is December 1998. Contact the IEEE Standards Department at 1 (732) 562-3800 for status information. See Footnote 6. 8 See Footnote 3. IEEE SOFTWARE REQUIREMENTS SPECIFICATIONS Std 830-1998 Copyright © 1998 IEEE. All rights reserved. 3 3. DeÞnitions In general the deÞnitions of terms used in this recommended practice conform to the deÞnitions provided in IEEE Std 610.12-1990. The deÞnitions below are key terms as they are used in t