This is the digital version of the printed book (Copyright © 1987). Here is a casebook, a practical reference, and an indispensable guide for creating a systematic, formal methodology for large, real-time, software-based systems.   The book introduces the widely implemented Hatley/Pirbhai methods, a major extension of the DeMarco analysis method describing how external events control the system's operating behavior. The techniques are used in major avionics and electronics companies worldwide, and are automated by most major CASE tools, including TurboCASE/Sys by StructSoft, Inc.   Large software-based systems, especially those for real-time applications, require multi-mode operation, direct interaction with a rapidly changing physical environment, and fast response times. In the past, the development of such systems was prone to massive cost and schedule overruns, and to inadequate performance and reliability. Strategies for Real-Time System Specification addresses these problems by integrating a finite-state machine structure into classical analysis methods.   The book contains nearly 200 diagrams, many of which illustrate the requirements specification of a flight management system for a major avionics developer.  

Table of Contents:
List of Figures        xv Foreword        xxiii Preface         xxv     Part I: The Overall Strategy         1 Chapter 1: Overview        3 1.1  The Birth of the Requirements Model   4 1.2  The Birth of the Architecture Model   7 1.3  Compatibility of the Models   7 1.4  Applicability of the Models   8 1.5  The System Life Cycle   8 Chapter 2: The Role of the Methods         11 2.1  Structured Methods: What They Are   11 2.2  System Requirements Model   13 2.3  System Architecture Model   19 2.4  System Specification Model   25 2.5  The Development Life Cycle   27 2.6  Structured Methods: What They Are Not   31 2.7 Summary   32   PART II: The Requirements Model        33 Chapter 3: Overview           35 3.1  The Structure of the Model        37   Chapter 4: The Process Model        41 4.1  Data Context Diagrams   41 4.2  Data Flow Diagrams   44 4.3  Leveling and Balancing   47 4.4  The Numbering System   49 4.5  Data Flows   49 4.6  Data Stores   52 4.7  Process Specifications   53 4.8  Interpreting the Process Model   56 4.9  Summary   59   Chapter 5: The Control Model         61 5.1  Control Context Diagrams    61 5.2  Control Flow Diagrams   64 5.3  Control Flows   67 5.4  Data Conditions   69 5.5  Control Stores   70 5.6  Control Specifications   70 5.7  Process Controls   73 5.8  Summary   76   Chapter 6: Finite State Machines        77 6.1  Combinational Machines   79 6.2  Sequential Machines   83 6.3  Incorporating Finite State Machines into CSPECs   89 6.4  Summary   97   Chapter 7: Timing Requirements        98 7.1  Repetition Rate   99 7.2  Input-to-Output Response Time   99 7.3  Summary   102   Chapter 8: Requirements Dictionary        103 8.1  Primitive Attributes   104 8.2  Group Structure   105 8.3  Dictionary Data Bases   107 8.4  Summary   110   Chapter 9: Requirements Model Interpretation and Summary         111 9.1  The Requirements Model Interpreted    111 9.2  Requirements Model Summary   113   PART III: Building the Requirements Model         117 Chapter 10: Overview        119 10.1  Model Users and Builders   119 10.2  The Sources of Requirements   120 10.3  The Model Building Process   121   Chapter 11: Getting Started        124 11.1  User Requirements Statements   124 11.2  Separating Data and Control   125 11.3  Establishing the System Context   129 11.4  Partitioning the Top Levels   132 11.5  Summary   135   Chapter 12: Developing the Model's Structure        137 12.1  Abstraction and Decomposition   137 12.2  The Seven-Plus-or-Minus-Two Principle   138 12.3  Grouping and Decomposing Processes   139 12.4  Grouping and Decomposing Flows   140 12.5  Naming Processes and Flows   147 12.6  Use of Stores   149 12.7  Functionally Identical Processes   150 12.8  De-emphasizing the Control Model   151 12.9    Control Intensive Systems   153 12.10  The Dilemma of Detail: Requirements Versus Design   155 12.11  The Final Product   156 12.12  Summary   156   Chapter 13: Preparing Process Specifications        158 13.1  The Role of Process Specifications   158 13.2  The Different Types of PSPECs   159 13.3  Some Important Signal Conventions   162 13.4  Structured English   165 13.5  Annotating with Comments   167 13.6  Summary   167   Chapter 14: Preparing Control Specifications        169 14.1  Avoiding Control Specifications   169 14.2  Combinational Control   170 14.3  Sequential Control   176 14.4  Multi-Sheet CSPECs   182 14.5  Fitting CSPECs In   185 14.6  Summary   189   Chapter 15: Defining Timing         190 15.1  Timing Overview   190 15.2  Response Time Specification   192 15.3  Summary   193   Chapter 16: Managing the Dictionary          194 16.1  Flow Types   194 16.2  Dictionary Symbols   198 16.3  Summary   199   PART IV: The Architecture Model         201 Chapter 17: Overview          203 17.1  Requirements-to-Architecture Template   204 17.2  Architecture Model Symbols   207   Chapter 18: Architecture Diagrams         211 18.1       Architecture Context Diagrams   211 18.2       Flows and Interconnects   213 18.3       Architecture Flow Diagrams   213 18.4       Architecture Interconnect Diagrams   218 18.5       Summary   224   Chapter 19: Architecture Dictionary and Module Specifications         225 19.1  Architecture Module Specification   226 19.2  Architecture Interconnect Specification   229 19.3  Timing Requirements   232 19.4  Architecture Dictionary   233 19.5  Summary   234   Chapter 20: Completing the Architecture Model          235 20.1  Allocation to Hardware and Software   235 20.2  The Hardware and Software Architectures   236 20.3  The Complete Architecture Model   238   PART V: Building the Architecture Model        241 Chapter 21: Overview        243 21.1  Architecture Development Process   244 21.2  Systems Come in Hierarchies   246   Chapter 22: Enhancing the Requirements Model        248 22.1  Input and Output Processing   249 22.2  User Interface Processing   251 22.3  Maintenance and Self-Test Processing   254 22.4  The Complete Enhanced Requirements Model   256 22.5  Technology-Independent Versus Technology-Nonspecific   257 22.6  Organizational Implications   260 22.7  Summary   261 Chapter 23: Creating the System Architecture Model         263 23.1  Architecture Context Diagram   263 23.2  Architecture Flow and Interconnect Diagrams   264 23.3  Example of AFD and AID Mapping   266 23.4  Model Consistency and Balancing   268 23.5  The Complete Architecture Model   271 23.6  Summary   272   Chapter 24: Creating the Hardware and Software Architecture Models        273 24.1  Hardware and Software Partitioning   276 24.4  Applying the Template to Software Requirements    279 24.3  Developing the Software Architecture   282 24.4  The Hardware and Software Architecture Process   284 24.5  Summary   285     Chapter 25: Architecture Development Summary         286 25.1 Partitioning the Modeling Process   286   PART VI: Examples        293 Chapter 26: Automobile Management System           295  26.1  Problem Statement   295 26.2  Requirements and Architecture Development   297 26.3  Requirements Model   299 26.4  Architecture Model   319   Chapter 27: Home Heating System         326 27.1  Problem Statement  326 27.2  Requirements Model   330 27.3  Architecture Model   340   Chapter 28: Vending Machine         342 28.1  Customer Dialogue    342 28.2  Requirements Model   344 28.3  Architecture Model   355   Appendices         363 Appendix A: Standard Symbols and Definitions          363 A.1    Introduction   363 A.2    Standard Symbols   363 A.3    Requirements Model   367 A.4    Architecture Model   382   Appendix B:  Making the Models into Documents        392 B.1  Organizing the Models   392 B.2  Military Standards   396   Appendix C:  Information Modeling: The Third Perspective        398   References         403 Index           405