Requirements Engineering Management Handbook

1 DOT/FAA/AR-08/32 Air Traffic Organization NextGen & Operations Planning Office of Research and technology Development Washington, DC 20591 Requirements Engineering Management Handbook June 2009 Final Report This document is available to the public through the National Technical Information Service (NTIS), Springfield, Virginia 22161. Department of Transportation federal aviation administration NOTICE This document is disseminated under the sponsorship of the Department of Transportation in the interest of information exchange.

2 The United States Government assumes no liability for the contents or use thereof. The United States Government does not endorse products or manufacturers. Trade or manufacturer's names appear herein solely because they are considered essential to the objective of this report. This document does not constitute FAA certification policy. Consult your local FAA aircraft certification office as to its use. This report is available at the federal aviation administration William J.

3 Hughes Technical Center s Full-Text Technical Reports page: in Adobe Acrobat portable document format (PDF). Technical Report Documentation Page 1. Report No. DOT/FAA/AR-08/32 2. Government Accession No. 3. Recipient's Catalog No. 4. Title and Subtitle Requirements Engineering Management Handbook 5. Report Date June 2009 6. Performing Organization Code 7. Author(s) David L. Lempia and Steven P. Miller 8. Performing Organization Report No. 9. Performing Organization Name and Address Rockwell Collins, Inc.

4 10. Work Unit No. (TRAIS) 400 Collins Road NE Cedar Rapids, Iowa 52245 11. Contract or Grant No. DTFACT-05-C-00004 12. Sponsoring Agency Name and Address Department of Transportation federal aviation administration Air Traffic Organization NextGen & Operations Planning Office of Research and technology Development 13. Type of Report and Period Covered Final Report Washington, DC 20591 14. Sponsoring Agency Code AIR-120 15. Supplementary Notes The federal aviation administration Airport and Aircraft Safety R&D Division COTR was Charles Kilgore.

5 16. Abstract This Handbook presents a set of recommended practices on how to collect, write, validate, and organize Requirements . It attempts to bring together the best ideas from several approaches, organize them into a coherent whole, and illustrate them with concrete examples that make their benefits clear. The Handbook is targeted to the domain of real-time, embedded systems and specifically to the avionics industry. It describes a set of recommended practices in which basic concepts can be practiced in isolation, but reinforce each other when practiced as a whole.

6 These practices allow developers to progress from an initial, high-level overview of a system to a detailed description of its behavioral and performance Requirements . Due to the growing importance of software in avionics systems, these practices emphasize techniques to ease the transition from system to software Requirements . Concrete examples are used throughout the Handbook to make the concepts clear, but there are many other formats that could be used to obtain the same objectives.

7 It is expected that most organizations wanting to use these practices will want to modify them, perhaps significantly, to integrate them with their existing processes and tools. 17. Key Words Requirements , Engineering , Avionics, Systems, Software 18. Distribution Statement This document is available to the public through the National Technical Information Service (NTIS) Springfield, Virginia 22161. 19. Security Classif. (of this report) Unclassified 20.

8 Security Classif. (of this page) Unclassified 21. No. of Pages 146 22. Price Form DOT F (8-72) Reproduction of completed page authorized TABLE OF CONTENTS Page EXECUTIVE SUMMARY xi 1. INTRODUCTION 1 Purpose 1 Background 2 2. RECOMMENDED PRACTICES Develop the System Overview 4 Develop System Overview Early 5 Provide System Synopsis 6 Identify System Contexts 6 Use Context Diagrams 7 Describe External Entities 7 Capture Preliminary System Goals 7 Maintain System Goal Information 8 Identify the System Boundary 9 Identify the System Boundary Early 10 Choose Environmental

9 Variables 11 Choose Controlled Variables 12 Choose Monitored Variables 12 Ensure Environmental Variables are Sufficiently Abstract 12 Avoid Presentation Details in Environmental Variables 12 Define All Physical Interfaces 13 Develop the Operational Concepts 14 Document Sunny Day System Behavior 16 Include How the System is Used in its Operating Environment 17 Employ the Use Case Goal as its Title 18 Trace Each Use Case to System Goals 18 Identify Primary Actor, Preconditions.

10 And Postconditions 18 Ensure Each Use Case Describes a Dialogue 18 iii Link Use Case Steps to System Functions 19 Consolidate Repeated Actions Into a Single Use Case 19 Describe Exceptional Situations as Exception Cases 19 Describe Alternate Ways to Satisfy Postconditions as Alternate Courses 19 Use Names of External Entities or Environmental Variables 20 Avoid Operator Interface Details 20 Update the System Boundary 20 Assemble a Preliminary Set of System Functions 21 Identify the Environmental Assumptions 22 Define the Type, Range, Precision.