System Requirements Analysis (eBook)

Front cover 1
Title page 4
Copyright page 5
Table of Contents 6
List of Illustrations 16
List of Tables 20
Preface 22
Acknowledgments 24
1 PART 1, INTRODUCTION 26
1.1 Introduction to System Requirements Analysis 28
1.1.1 The Human Foundation 29
1.1.2 What Is a System? 29
1.1.3 What Is System Development? 30
1.1.4 The Fundamental System Relation 31
1.1.5 What Is System Requirements Analysis? 32
1.1.6 System Requirements Analysis Timing Considerations 34
1.1.7 Development Approaches 35
1.1.8 Degree of Precedence Alternatives 36
1.1.9 Organizational Alternatives 36
1.1.10 Data Environment Alternatives 38
1.1.11 Some History and References 38
1.1.12 Overview of the Book 39
1.1.12.1 How It Came to Be 39
1.1.12.2 The Remainder of This Part 39
1.1.12.3 The Other Parts of This Book 40
1.1.13 How to Get the Most Out of the Book 42
1.2 System Development Process Overview 43
1.2.1 The Ultimate Process Step—The Enterprise Vision 44
1.2.2 Product-Line Effects 45
1.2.3 Customer-Base Effects 45
1.2.4 Structured Process Analysis and Process Definition Expansion 46
1.2.5 Documentation Media 49
1.2.6 Lower-Tier Development Functionality 49
1.2.6.1 Grand Systems Requirements, F41 49
1.2.6.1.1 Program Integration 51
1.2.6.1.1.1 Initial System Analysis 51
1.2.6.1.1.2 Publish Specifications, F4122 53
1.2.6.1.1.3 Traditional Structured Analysis, F4113 53
1.2.6.1.2 Computer Software Structured Analysis, F4114 55
1.2.6.1.3 Validate Requirements, F4121 55
1.2.7 Grand Systems Synthesis, F42 57
1.2.7.1 Design Grand System, F421 57
1.2.7.1.1 Item Team Preliminary Design, F4211 57
1.2.7.1.2 Item Team Detailed Design, F4212 57
1.2.7.2 Material Operations, F422 57
1.2.7.3 Manufacture System, F423 57
1.2.8 Grand Systems Verification, F44 57
1.2.9 Grand Systems Sustainment, F48 61
1.2.9.1 Logistical Support System, F482 and F483 61
1.2.9.2 Deploy/Deliver Product System, F481 61
1.2.9.3 Modify Product System, F484 61
1.2.9.4 Dispose of the System, F485 61
1.2.10 Use Product System, F47 61
1.2.11 Manage Program, F49 61
1.2.12 Assure Product and Process Quality, F46 62
1.3 Process Variations 63
1.3.1 The Situation 64
1.3.1.1 The Central Model 64
1.3.1.2 DoD Process Rationale 64
1.3.1.3 Other U.S. Government Life-Cycle Models 65
1.3.1.4 Commercial Firm Future 65
1.3.1.5 The JOG System Engineering Prescription for Specifications 66
1.3.1.5.1 Template Preparation 67
1.3.1.5.2 Map Templates to Functional Departments 67
1.3.1.5.3 Map Templates to Structured Analysis Models 67
1.3.1.5.4 Provide for Configuration Management of the Model Base 67
1.3.1.5.5 Perform Structured Analysis on Programs 67
1.3.1.5.6 Allocate All Requirements to Product Architecture 67
1.3.1.5.7 Coordinate RAS-Complete with Template Structure 67
1.3.1.5.8 Capture Modeling Work Products in SDD 67
1.3.2 Alternative Sequence Models 67
1.3.3 Concentrated Versus Distributed Customer Base 67
1.3.4 Precedented Versus Unprecedented Systems 67
1.3.5 The Three Gross Models 68
1.3.6 The Lowest Common Denominator 69
2 PART 2, REQUIREMENTS FOUNDATION 70
2.1 Requirements Fundamentals 72
2.1.1 Primitive Requirements Statement 73
2.1.1.1 The Essence of a Requirement 73
2.1.1.2 Document Style and Format 73
2.1.1.3 Primitive Requirement Statement Conversion 75
2.1.1.4 Total Effect of Changes 75
2.1.1.5 Variations 75
2.1.1.6 Document Example 76
2.1.2 Requirements Value Definition Methods 76
2.1.2.1 Why Is Quantification Important? 76
2.1.2.2 Value Definition Methods 76
2.1.3 Requirements Derivation 78
2.1.4 Kinds of Requirements 79
2.1.4.1 Performance Requirements 79
2.1.4.2 Design Constraints 79
2.1.4.2.1 What Is a Design Constraint? 79
2.1.4.2.2 Design Constraints Analysis Timing 79
2.1.4.2.3 Major Design Constraint Categories 80
2.1.5 Requirements in Time 80
2.1.6 The Remaining Road 81
2.2 Requirements Traceability Relationships 82
2.2.1 Requirements Are Not Islands 83
2.2.2 Vertical Traceability 83
2.2.2.1 Requirements Source Traceability 83
2.2.2.2 Requirements Rationale Traceability 84
2.2.2.3 Requirements Traceability and Allocation/Flow Down 84
2.2.2.4 Parent-Child Requirements Traceability 85
2.2.2.4.1 Why Traceability? 85
2.2.2.4.2 Traceability Mechanism 86
2.2.2.4.3 Traceability Across Interfaces 86
2.2.2.4.4 Multiple Traceability Paths 87
2.2.3 Longitudinal Traceability 87
2.2.4 Requirements Traceability to Process 88
2.2.4.1 Single Sheet Traceability to Process 89
2.2.4.2 Specification Template Traceability 90
2.2.5 Grand System Traceability 90
2.2.6 Traceability Reporting 91
2.2.7 Traceability Audits 93
2.3 Requirements Allocation, Margins, and Budgets 94
2.3.1 Requirement Value Determination 95
2.3.2 Requirements Allocation 95
2.3.3 Margin Management 95
2.3.3.1 What Are Formal Margins? 95
2.3.3.2 Selection and Maintenance of Design Margin Parameters 97
2.3.3.3 Safety Margins 97
2.3.3.4 Inclusion of Margin Accounts in Requirements Data 98
2.3.3.5 Design Margin Account Transfers 98
2.3.4 Budget Management 98
2.4 Requirements Analysis Strategies 99
2.4.1 The Four Strategies 100
2.4.2 Freestyle Strategy 100
2.4.3 Cloning Strategy 100
2.4.3.1 Specification Standards 101
2.4.3.2 Like Item Approach 102
2.4.3.3 Parent Item, Flow Down, or Allocation Approach 102
2.4.3.4 Flow Down Scope Limitation 103
2.4.4 Question and Answer Strategy 103
2.4.5 Structured Analysis Strategy 103
3 PART 3, TRADITIONAL STRUCTURED ANALYSIS 106
3.1 System Beginnings 108
3.1.1 What’s in a Name? 109
3.1.2 In the Beginning 109
3.1.3 The Meaning of the Term 109
3.1.4 Unprecedented System Definition 109
3.1.4.1 Customer Interaction 111
3.1.4.2 Mission and Operations Analysis 112
3.1.4.3 MOE and Selection Criteria Development 112
3.1.4.4 Requirements Work 113
3.1.4.5 System Environmental Definition 113
3.1.4.6 Specialty Discipline Analyses 114
3.1.4.7 Concept and Program Design 114
3.1.4.8 Manage the Study 115
3.1.4.9 Program Funding Profile Requirements 115
3.1.5 Trade Studies 116
3.1.5.1 Trade Study Mechanics 116
3.1.5.2 Post Selection Tasks 118
3.1.6 Rigor Versus Creativity 118
3.1.7 Precedented System Definition 118
3.1.8 Concluding Reviews 119
3.2 A General Theory of Structured Analysis 120
3.2.1 What Is Structured Analysis? 121
3.2.2 Structured Analysis Goals 121
3.2.3 Where Does It Appear in the Process? 121
3.2.4 Comparative Overview of Approaches 124
3.2.5 Polyfaceted View of Problem Spaces 124
3.2.6 Entry Facet Differences 125
3.2.7 An Entry Continuum 126
3.2.8 Model Documentation 126
3.2.9 Completeness and Avoiding Model Madness 127
3.2.10 Detailed Coverage of Models 129
3.3 Functional Analysis 130
3.3.1 The Heritage of Structured Analysis 131
3.3.2 Form Follows Function 131
3.3.3 Functional Flow Analysis 133
3.3.3.1 Function Identification and Sequence 133
3.3.3.2 The Top Function 136
3.3.3.3 Life-Cycle Master Flow Diagram 137
3.3.3.4 Flow Diagramming Details 138
3.3.3.5 Detailed Flow Diagrams 139
3.3.3.6 Functional N-Square Diagramming 141
3.3.3.7 Performance Requirements Analysis 142
3.3.3.8 Allocation Pacing 142
3.3.3.8.1 Independent Mode 142
3.3.3.8.2 Instant Allocation Mode 142
3.3.3.8.3 Progressive Allocation Mode 142
3.3.3.8.4 Layered Approach 142
3.4 Product and Process Performance Requirements Analysis and Allocation 143
3.4.1 Preliminaries 144
3.4.1.1 Product Performance Requirements Analysis 144
3.4.1.2 Process Performance Requirements Analysis 145
3.4.2 Requirements Development Strategies 145
3.4.3 The General Plan 145
3.4.4 Transition to Process Analysis 146
3.4.5 Primitive Statement and Transform 148
3.4.6 Value Identification 148
3.4.7 Product Class Differences 148
3.4.7.1 Product Computer Software 148
3.4.7.2 Operational and Logistics Task Analysis 148
3.4.7.3 Product Facilities 149
3.4.7.4 Composite Product Objects 149
3.4.8 Guidelines 149
3.4.9 Verification Planning Analysis (VPA) 150
3.4.9.1 Overview 150
3.4.9.2 Development Evaluation Test Requirements Analysis 151
3.4.9.3 Item Qualification Verification Requirements Analysis 151
3.4.9.4 System Test and Evaluation Requirements Analysis 151
3.4.9.5 Item Acceptance Test Requirements Analysis 152
3.4.10 Logistics Support Analysis 152
3.4.11 Allocation of Functionality 153
3.4.11.1 Team Briefing 156
3.4.11.2 Review Past Allocations 156
3.4.11.3 Brainstorming and Analysis 156
3.4.11.4 Consolidation 157
3.4.11.5 New Architecture Identification 158
3.4.11.6 Engineering Review Meeting 158
3.4.11.7 Overall Coordination 158
3.4.11.8 Allocation Criteria Guidance 158
3.4.11.9 Additional Performance Requirements Analysis Examples 159
3.4.11.9.1 Performance Requirements Analysis Example 1 159
3.4.11.9.2 Performance Requirements Analysis Example 2 160
3.4.11.9.3 Performance Requirements Analysis Example 3 160
3.4.11.9.4 Performance Requirements Analysis Example 4 160
3.4.12 Performance Requirements Analysis Preceding Function Allocation 161
3.4.13 RAS-Centered Requirements Analysis 161
3.4.14 Process Summary 161
3.5 Architecture Synthesis 163
3.5.1 Introduction to Architecture 164
3.5.2 Architecture Block Diagramming 164
3.5.3 Diagramming Fundamentals 165
3.5.4 Architecture Element Coding 166
3.5.5 Sheet Cross-Referencing 167
3.5.6 Alternative Organizational Structures 167
3.5.7 Implementation Notes and Responsibility 168
3.5.8 Architecture Crossing Conditions 168
3.5.9 Reversing Traditional Structured Analysis 170
3.6 Interface Identification and Definition 173
3.6.1 Introduction to Interface Analysis 174
3.6.1.1 Interface Defined 174
3.6.1.2 The Interface Dilemma 175
3.6.1.3 The Solution 175
3.6.2 Interface Identification 175
3.6.2.1 Intuitive Interface Identification 175
3.6.2.2 A Thoroughly Disciplined Method 176
3.6.3 Identification Work Products 177
3.6.3.1 N-Square Diagramming Methods 178
3.6.3.2 Schematic Methods 179
2.6.3.3 Interface Dictionary 182
3.6.4 Interface Media and Requirements Definition 184
3.6.4.1 Electrical Power Example 186
3.6.4.2 Electrical Signal Example 186
3.6.4.3 Physical Attachment Example 186
3.6.4.4 Fluid Transmission Example 186
3.6.5 Interface Documentation 186
3.6.5.1 Capture in the Requirements Analysis Sheet and Database System 186
3.6.5.2 Interface Definition Publication 187
3.6.6 Interface Responsibility 187
3.6.6.1 Program Organization 187
3.6.6.2 Three Views of Interface 187
3.6.6.3 Interface Responsibility Model 188
3.6.6.4 The Special Need for External Interface Development 190
3.7 Specialty Engineering Requirements Analysis 193
3.7.1 Serial Versus Parallel Work Pattern 194
3.7.2 The Generic Specialty Engineering Process 194
3.7.2.1 Requirements Identification Responsibility Aid 194
3.7.2.2 Requirements Capture 195
3.7.2.2.1 Freestyle Approach 195
3.7.2.2.2 Cloning Approach 195
3.7.2.2.3 Question and Answer Approach 196
3.7.2.2.4 The Structured Strategy in Years Gone By 196
3.7.2.2.5 Structured Analysis in the Twenty-First Century 196
3.7.2.3 Constraints Integration 197
3.7.2.4 Specialty Constraints Communication 197
3.7.2.4.1 Checklist Approach 197
3.7.2.4.2 Individual Person-to-Person 198
3.7.2.4.3 Organized Interaction Meetings 198
3.7.2.4.4 Decision Support 199
3.7.2.5 Specialty Design Assessment 199
3.7.2.5.1 Non-Compliance Identification 199
3.7.2.5.2 Non-Compliance Correction 199
3.7.3 Engineering Specialty Activities Overview 200
3.7.3.1 Reliability Engineering 200
3.7.3.1.1 Task 1, Reliability Program Plan 200
3.7.3.1.2 Task 2, Subcontractor and Supplier Control 200
3.7.3.1.3 Task 3, Failure Reporting, Analysis, and Corrective Action System (FRACAS) 200
3.7.3.1.4 Task 4, Failure Review Board (FRB) 201
3.7.3.1.5 Task 5, Reliability Modeling 201
3.7.3.1.6 Task 6, Reliability Allocations 201
3.7.3.1.7 Task 7, Reliability Predictions 201
3.7.3.1.8 Task 8, Failure Modes, Effects, and Criticality Analysis (FMECA) 201
3.7.3.1.9 Task 9, Reliability Critical Items and Critical Item Control Plan 202
3.7.3.1.10 Task 10, Reliability Development, Growth, and Test (RDG& T) Plan
3.7.3.1.11 Task 11, Sneak Circuit Analysis 202
3.7.3.1.12 Reliability References 202
3.7.3.2 Parts, Materials, and Process Engineering (PMP) 202
3.7.3.3 Maintainability Engineering 203
3.7.3.3.1 Task 1, Maintainability Analysis 204
3.7.3.3.2 Task 2, Document Maintainability Requirements and Criteria 204
3.7.3.3.3 Task 3, Maintainability Quantitative Analysis to Assure Requirements Are Met 205
3.7.3.3.4 Task 4, Design Surveillance/Assessment 205
3.7.3.3.5 Task 5, Participate in Design Tradeoff Studies 205
3.7.3.3.6 Task 6, Participate in Design Reviews 205
3.7.3.3.7 Task 7, Subcontractor and Supplier Control 205
3.7.3.3.8 Task 8, Failure Reporting, Analysis, and Corrective Action 205
3.7.3.3.9 Task 9, Conduct Maintainability Demonstration 206
3.7.3.3.10 Maintainability References 206
3.7.3.4 Availability 206
3.7.3.5 Producibility Engineering 206
3.7.3.6 Design to Cost/Life-Cycle Cost (DTC/LCC) 207
3.7.3.7 Human Factors Engineering 207
3.7.3.8 Corrosion Prevention and Control (CPC) 208
3.7.3.9 System Safety Engineering 208
3.7.3.10 Electromagnetic Compatibility (EMC) Engineering 208
3.7.3.11 System Security Engineering 208
3.7.3.12 Mass Properties Engineering 208
3.7.3.13 Environmental Impact Engineering 209
3.7.4 Science Projects and Natural Systems 209
3.7.4.1 The Ultimate System Diagram 209
3.7.4.2 Give Us the Sense to Know the Difference 210
3.7.4.3 Characterizing Reality 211
3.7.4.4 Specific Science Development Programs 211
3.8 Environmental Requirements Analysis 212
3.8.1 Overview 213
3.8.2 Environmental Categories 213
3.8.2.1 Natural Environment (QN) 213
3.8.2.2 Self-Induced Environment (QI) 214
3.8.2.3 Non-Cooperative Environment (QX) 214
3.8.2.4 Hostile Environment (QH) 215
3.8.2.5 Cooperative Environment (QC) 215
3.8.3 Environmental Requirements Models 215
3.8.3.1 System Environmental Requirements Analysis 215
3.8.3.2 End Item Environmental Requirements 215
3.8.3.3 Component Environmental Requirements 219
3.8.4 Time Analysis 220
3.8.4.1 Diagramming Fundamentals 220
3.8.4.2 Timeline Diagram Symbols 220
3.8.4.3 Variability 221
3.8.4.4 Selectivity 221
3.8.4.5 Tabular Timelines 222
3.8.4.6 Timeline Reporting 223
3.8.5 Environmental Requirements Capture 224
3.8.6 Environmental Impact 224
3.9 Functional Analysis Alternatives 225
3.9.1 Variations Covered 226
3.9.2 Functional Analysis Variations 226
3.9.2.1 Hierarchical Functional Analysis 226
3.9.2.2 Enhanced Functional Flow Block Diagramming 227
3.9.2.2.1 Trigger Construct 227
3.9.2.2.2 Multiple Exit Function 227
3.9.2.2.3 Iteration 227
3.9.2.2.4 Loop 227
3.9.2.2.5 Kill Branch 227
3.9.2.2.6 Lateral Data or Commodity Flow 228
3.9.2.3 Behavioral Diagramming 228
3.9.2.4 IDEF-0 229
3.9.2.5 FRAT 230
3.9.3 State and Event Analysis 231
3.9.3.1 State Transition Diagram Analysis 231
3.9.3.2 Finite State Machines 233
3.9.3.3 Petri Nets 234
3.9.3.4 Event Traces, Lists, and Trees 235
3.9.4 Mathematical Models 235
3.9.4.1 Mathematical Equations 235
3.9.4.2 Formal Methods 236
3.9.5 Scenarios, Strings, and Threads Analysis 236
3.9.5.1 Scenario Depictions 236
3.9.5.2 Icon Flow 236
3.9.5.3 Descriptive Text 236
3.9.5.4 Strings or Threads 236
3.9.5.5 Synthesis of Functional Threads 237
3.9.6 Process Analysis 237
3.9.6.1 Process Fundamentals 237
3.9.6.1.1 Diagramming 237
3.9.6.1.2 Process-Resource Linkage 239
3.9.6.1.3 Process-Environment Linkage 239
3.9.6.2 Process Analysis Applications 240
3.9.6.2.1 Generic Enterprise and Program Planning 240
3.9.6.2.2 Generic Process Analysis 240
3.9.6.2.3 Program Specific Process 241
3.9.6.2.4 Continuing Cost and Schedule Requirements Analysis 241
3.9.6.3 Program Product-Oriented Processes 241
3.9.6.3.1 Specialty Engineering Integration and Concurrent Engineering 241
3.9.6.3.2 Program Material and Procurement Process Analysis 241
3.9.6.3.3 Program Manufacturing and Quality Process Analysis 242
3.9.6.3.4 Program Verification Process Analysis 242
3.9.6.3.4.1 Test Planning Analysis (TPA) 242
3.9.6.3.4.2 Development Test Requirements Analysis 243
3.9.6.3.4.3 Qualification Test Requirements Analysis 244
3.9.6.3.4.4 Operational Test Requirements Analysis 244
3.9.6.3.4.5 Acceptance Test Requirements Analysis 244
3.9.6.4 Deployment Planning Analysis (DPA) 244
3.9.6.5 System Sustainment Process Analysis 245
3.9.6.5.1 Logistics Support Analysis Overview 245
3.9.6.5.2 LSA Example 245
3.9.6.5.3 Product Operation Analysis 248
3.9.6.5.4 Modification Development 248
3.9.6.6 Disposal Analysis 251
3.9.7 Quality Function Deployment 252
3.9.7.1 Introduction to Quality Function Deployment (QFD) 252
3.9.7.2 Physical Implementation 253
3.9.7.3 A Problem With QFD 254
3.9.7.4 Linking QFD with Structured Analysis 254
3.9.7.5 Derived Requirements Generator 255
3.10 RAS-Complete and RAS-Centered Analysis 256
3.10.1 A System Defined 257
3.10.2 Descriptors of Interest 257
3.10.3 System Functionality 257
3.10.4 Performance Requirements Derivation and Allocation 259
3.10.5 Conventional RAS Limitations 259
3.10.6 The Beginning of the Complete RAS 259
3.10.7 System Architecture 260
3.10.8 Allocation Pacing Alternatives 260
3.10.9 System Relations 261
3.10.10 The System Environment 262
3.10.11 Environmental Relation Algorithm 263
3.10.11.1 System Environmental Relations 263
3.10.11.2 End Item Service Use Profile 263
3.10.11.3 Component Environmental Relations 265
3.10.12 Specialty Engineering and RAS Complete 266
3.10.13 Verification Extension 267
3.10.14 Conclusions 267
3.11 Traditional Structured Analysis Documentation 268
3.11.1 The Common Failure 269
3.11.2 SDD Content and Format 269
3.11.2.1 Document Main Body 269
3.11.2.2 Appendix A, Functional Analysis 269
3.11.2.3 Appendix B, System Environment Analysis 269
3.11.2.4 Appendix C, System Architecture Analysis 269
3.11.2.5 Appendix D, System Interface Analysis 269
3.11.2.6 Appendix E, Specialty Engineering Definition Analysis 269
3.11.2.7 Appendix F, System Process Analysis 269
3.11.2.8 Appendix G, Requirements Analysis Sheet 269
3.11.3 Recommended Responsibility Pattern 271
4 PART 4, COMPUTER SOFTWARE STRUCTURED ANALYSIS 274
4.1 Introduction 276
4.1.1 Computer Software Development Environment 277
4.1.2 Software Development Models for Analysis 277
4.1.3 Model Comparisons 278
4.1.4 Design and Manufacturing Differences 278
4.1.5 Software Deficit Disorder 278
4.2 Computer Processing–Oriented Analysis 280
4.2.1 A Little History 281
4.2.2 Flowcharts and Other Things 281
4.2.3 Modern Structured Analysis 281
4.2.4 Hatley–Pirbhai Real-Time Extension 285
4.2.5 Transform from Models to Software Entities and Their Requirements 285
4.2.6 Are These Models Appropriate Only for Software? 285
4.3 Data-Oriented Analysis 287
4.3.1 Data Augmentation of Modern Structured Analysis 288
4.3.1.1 Data Lines, Stores, and Dictionaries 288
4.3.1.2 Entity Relationship Diagrams 288
4.3.2 Relational Database Development 288
4.3.2.1 Relational Database Development Using Table Normalization 288
4.3.2.2 Relational Database Development Using IDEF 1X 288
4.3.3 Transition to Specification 289
4.3.4 DoD Architecture Framework 289
4.4 Object-Oriented Analysis 290
4.4.1 The Early Combined Analysis Techniques 291
4.4.1.1 Input-Process-Output (IPO) Analysis 291
4.4.1.2 SADT and IDEF-0 291
4.4.2 Early Object-Oriented Analysis 292
4.4.2.1 A Dynamic Beginning 292
4.4.2.2 Misplaced Beginnings 292
4.4.2.3 The Class and Object Model 292
4.4.2.4 The Dynamic Model 293
4.4.2.5 The Functional Model 293
4.4.3 Function-Driven Early OOA 294
4.4.4 Unified Modeling Language (UML) 295
4.4.4.1 Problem Space Entry and Continuation 295
4.4.4.2 Dynamic Model Elements 296
4.4.4.2.1 Use Case Diagram 296
4.4.4.2.2 Statechart Diagram 296
4.4.4.2.3 Activity Diagram 296
4.4.4.2.4 Collaboration Diagram 297
4.4.4.2.5 Sequence Diagram 297
4.4.4.3 Static Model Elements 297
4.4.4.3.1 Class and Object Diagrams 298
4.4.4.3.2 Component and Deployment Diagrams 298
4.4.4.4 Unprecedented Application 298
4.4.4.5 Precedented Application 299
4.4.5 Moving to Specification 299
4.5 System Modeling Using the DoD Architecture Framework 300
4.5.1 Background 301
4.5.2 Overview 301
4.5.3 Framework Products 302
4.5.3.1 All Views 302
4.5.3.1.1 Overview and Summary Information (AV-1) 302
4.5.3.1.2 Integrated Dictionary (AV-2) 302
4.5.3.2 Operational Architecture Views 303
4.5.3.2.1 High-Level Operational Concept Graphic (OV-1) 303
4.5.3.2.2 Operational Node Connectivity Description (OV-2) 303
4.5.3.2.3 Operational Information Exchange Matrix (OV-3) 304
4.5.3.2.4 Organizational Relationships Chart (OV-4) 304
4.5.3.2.5 Activity Model (OV-5) 304
4.5.3.2.6 Operational Activity Sequence and Timing Descriptions (OV-6) 304
4.5.3.2.6.1 Operational Rules Model (OV-6a) 304
4.5.3.2.6.2 Operational State Transition Description (OV-6b) 304
4.5.3.2.6.3 Operational Event/Trace Description (OV-6c) 305
4.5.3.2.7 Logical Data Model (OV-7) 305
4.5.3.3 Systems View 306
4.5.3.3.1 System Interface Description (SV-1) 306
4.5.3.3.2 Systems Communications Description (SV-2) 306
4.5.3.3.3 Systems–Systems Matrix (SV-3) 307
4.5.3.3.4 Systems Functionality Description (SV-4) 307
4.5.3.3.5 Operational Activity to System Function Traceability Matrix (SV-5) 308
4.5.3.3.6 Systems Data Exchange Matrix (SV-6) 308
4.5.3.3.7 Systems Performance Parameters Matrix (SV-7) 308
4.5.3.3.8 Systems Evolution Description (SV-8) 308
4.5.3.3.9 Systems Technology Forecast (SV-9) 308
4.5.3.3.10 System Activity Sequence and Timing Descriptions (SV-10) 309
4.5.3.2.11 Physical Schema (SV-11) 309
4.5.3.4 Technical Standards View 309
4.5.3.4.1 Technical Architecture Profile (TV-1) 309
4.5.3.4.2 Standards Technology Forecast (TV-2) 309
4.5.4 Other Related Efforts 309
4.5.5 Architecture Product Interrelationships 309
4.5.5.1 Operational View Relationships 309
4.5.5.2 Systems View Relationships 310
4.5.5.3 Operations to Systems View Traceabilities 310
4.5.6 The Six-Step Architecture Description Process 310
4.5.6.1 Determine Intended Use of the Architecture 310
4.5.6.2 Determine Architecture Scope, Context, Environment, and Assumptions 310
4.5.6.3 Determine What Information the Architecture Description Needs to Capture 310
4.5.6.4 Determine Views and Products to Be Built 310
4.5.6.5 Build the Requisite Products 311
4.5.6.6 Use the Architecture for Its Intended Purpose 312
4.6 Structured Analysis Fusion and Reunification 313
4.6.1 Functional Flow or Die! 314
4.6.2 Structured Analysis Boundaries 315
4.6.2.1 Multiple Paths 315
4.6.2.1.1 Decomposition Methodology Flexibility 315
4.6.2.2 Functional Traceability 315
4.6.3 Expanding Zigzag 316
4.6.4 Evolution of the Ultimate Method 317
4.6.5 Model-Driven Development 317
5 PART 5, SPECIFICATION CONTENT STANDARDS 320
5.1 Specification Development Fundamentals 322
5.1.1 Overview 323
5.1.1.1 What Is a Specification? 323
5.1.1.2 Specification Format Control 323
5.1.1.3 Document Controls 323
5.1.1.4 The Case for Uniformity 323
5.1.2 DoD Specifications under MIL-STD-490A 323
5.1.2.1 MIL-STD-490A Specification Types 323
5.1.2.1.1 Type A System/Segment Specification 323
5.1.2.1.2 Type B Development Specifications 324
5.1.2.1.2.1 Type B1 Prime Item Development Specification 324
5.1.2.1.2.2 Type B2 Critical Item Development Specification 324
5.1.2.1.2.3 Type B3 Non-Complex Item Development Specification 325
5.1.2.1.2.4 Type B4 Facility or Ship Development Specification 325
5.1.2.1.2.5 Type B5 Software Development Specification 325
5.1.2.1.3 Type C Product Specifications 325
5.1.2.1.3.1 Type C1 Prime Item Product Specifications 326
5.1.2.1.3.2 Type C1a Prime Item Product Function Specification 326
5.1.2.1.3.3 Type C1b Prime Item Product Fabrication Specification 326
5.1.2.1.3.4 Type C2 Critical Item Product Specifications 326
5.1.2.1.3.5 Type C2a Critical Item Product Function Specification 326
5.1.2.1.3.6 Type C2b Critical Item Product Fabrication Specification 326
5.1.2.1.3.7 Type C3 Non-complex Item Product Fabrication Specification 326
5.1.2.1.3.8 Type C4 Inventory Item Specification 326
5.1.2.1.3.9 Type C5 Software Product Specification 326
5.1.2.1.4 Type D Process Specifications 326
5.1.2.1.5 Type E Material Specifications 326
5.1.2.2 DoD Specification Forms under MIL-S-83490 326
5.1.2.3 Coordinated MIL-STD-490A References 327
5.1.2.4 MIL-STD-490A Specification Baselines 327
5.1.2.4.1 Functional Configuration Identification 328
5.1.2.4.2 Allocated Configuration Identification 328
5.1.2.4.3 Product Configuration Identification 328
5.1.3 MIL-STD-961D Specification Standard 328
5.1.3.1 Specification Types 328
5.1.3.2 Structure and Content 328
5.1.4 MIL-STD-961E 328
5.1.5 Other Requirements Document Types 328
5.1.6 Coverage of Specifications 329
5.1.6.1 General Specification 329
5.1.6.2 Detail Specification 329
5.1.7 One- and Two-Part Specifications 329
5.1.8 A Strange Specification Format 330
5.2 General Specification Style Guide 331
5.2.1 Style, Format, and Identification of Military Specifications 332
5.2.1.1 Sectional Arrangement of Specifications 332
5.2.1.2 Language Style 332
5.2.1.3 Primitive Requirement Statement 332
5.2.1.4 Capitalization and Spelling 332
5.2.1.5 Abbreviations 332
5.2.1.6 Symbols 332
5.2.1.7 Proprietary Names 333
5.2.1.8 Commonly Used Words and Phrasing 333
5.2.1.9 Use of “Shall,” “Will,” “Should,” and “May” 333
5.2.1.10 Use of “Flammable” and “Nonflammable” 333
5.2.2 Paragraph Numbering and Identification 333
5.2.2.1 Paragraph Identification 333
5.2.2.2 Underlining 333
5.2.2.3 Cross-References 333
5.2.2.4 Figures, Tables, and Foldouts 333
5.2.2.5 Location of Figures in Specification 334
5.2.2.6 Preparation of Figures 334
5.2.2.7 Location of Tables in Specifications 334
5.2.2.8 Preparation of Tables 334
5.2.2.9 Foldouts 334
5.2.3 Footnotes 334
5.2.3.1 Footnotes to Text 334
5.2.3.2 Footnotes to Tables and Figures 334
5.2.4 Contractual and Administrative Requirements 334
5.2.4.1 Definitions in Specifications 334
5.2.4.2 References to Other Documents 334
5.2.4.3 Limitation on References 335
5.2.4.4 Security Marking of Specifications 335
5.2.4.5 Identification of Specifications 335
5.2.4.6 Titling the Specification 336
5.3 Specification Content Guidance 337
5.3.1 MIL-STD-490A Content Standard 338
5.3.1.1 Section 1: Scope 338
5.3.1.1.1 Scope 338
5.3.1.1.2 Classification 338
5.3.1.2 Section 2: Applicable Documents 338
5.3.1.2.1 Kinds of Documents Referenced 338
5.3.1.2.1.1 Government Documents 338
5.3.1.2.1.2 Non-Government Documents 338
5.3.1.2.2 Listing of References 339
5.3.1.2.2.1 Government Documents 339
5.3.1.2.2.2 Nongovernment Documents 339
5.3.1.3 Section 3: Requirements 339
5.3.1.3.1 Definition (Paragraph 3.1) 340
5.3.1.3.2 Characteristics (Paragraph 3.2) 340
5.3.1.3.2.1 Performance Characteristics 340
5.3.1.3.2.2 Physical Characteristics 340
5.3.1.3.2.2.1 Reliability 340
5.3.1.3.2.2.2 Maintainability 340
5.3.1.3.2.2.3 Environmental Conditions 340
5.3.1.3.2.2.4 Environmental Conditions Transportability 340
5.3.1.3.2.3 Design and Construction (Paragraph 3.3) 340
5.3.1.3.2.3.1 Materials 340
5.3.1.3.2.3.2 Materials: Toxic Products and Formulations 341
5.3.1.3.2.3.3 Electromagnetic Radiation 341
5.3.1.3.2.3.4 Nameplates or Product Markings 341
5.3.1.3.2.3.5 Workmanship 341
5.3.1.3.2.3.6 Interchangeability 341
5.3.1.3.2.3.7 Safety 341
5.3.1.3.2.3.8 Human Engineering 341
5.3.1.3.2.4 Documentation (Paragraph 3.4) 341
5.3.1.3.2.5 Logistics (Paragraph 3.5) 341
5.3.1.3.2.6 Personnel and Training (Paragraph 3.6) 341
5.3.1.3.2.7 Characteristics of Subordinate Elements (Paragraph 3.7) 341
5.3.1.3.2.8 Precedence (Paragraph 3.8) 341
5.3.1.3.2.9 Qualification (Paragraph 3.9) 341
5.3.1.4 Section 4: Quality Assurance Provisions 342
5.3.1.4.1 General 342
5.3.1.4.2 Responsibility for Inspection 342
5.3.1.4.3 Special Tests and Examinations 342
5.3.1.4.4 Quality Conformance Inspections 343
5.3.1.5 Section 5: Preparation for Delivery 343
5.3.1.5.1 General 343
5.3.1.5.2 Detailed Preparation 343
5.3.1.5.2.1 Preservation and Packaging 343
5.3.1.5.2.2 Packing 343
5.3.1.5.2.3 Marking for Shipment 343
5.3.1.6 Section 6: Notes 343
5.3.1.6.1 Intended Use 343
5.3.1.6.2 Ordering Data 344
5.3.1.6.3 Instructions for Models and Samples 344
5.3.1.6.4 Qualification Provisions 344
5.3.1.6.5 Cross-Reference of Classifications 344
5.3.1.6.6 Miscellaneous Notes 344
5.3.1.7 Appendix and Index 344
5.3.1.7.1 Appendix Numbering 344
5.3.1.7.2 Scope 344
5.3.1.7.3 Headings 344
5.3.1.7.4 References 344
5.3.1.7.5 Index 344
5.3.2 MIL-STD-961D Content Standard 344
5.3.3 MIL-STD-961E Content Standard Delta 345
5.3.4 Software Specification Standards 345
5.3.4.1 Military Standards 345
5.3.4.1.1 Software System Specification 345
5.3.4.1.2 Software Requirements Specification (SRS) 345
5.3.4.1.3 Software Product Specification (SPS) 345
5.3.4.1.4 Interface Requirements Specification (IRS) 345
5.3.4.2 Commercial Standards 345
5.3.5 A Standard For the Ultimate Simplicity 346
5.3.6 An Updated Content Standard 346
5.4 Applicable Documents Analysis 354
5.4.1 Introduction to Applicable Documents 355
5.4.1.1 Applicable Documents Defined 355
5.4.1.2 Bidirectional Tailoring 355
5.4.1.3 Document Tailoring 355
5.4.1.4 Applicable Document Levels 356
5.4.1.5 DoD Policy Changes 356
5.4.1.6 Definitions 356
5.4.2 Initiation of the Program-Applicable Documents List 356
5.4.2.1 An Enterprise-Applicable Documents List (EADL) 356
5.4.2.2 Applicable Document Assessment Sources 356
5.4.3 Detailed Process Description 358
5.4.3.1 Create and Maintain Program-Applicable Document List, F3131 358
5.4.3.2 Coordinate Tailoring Capture, F3132 360
5.4.3.3 Maintain EADL 360
5.4.3.4 Compare Requirements, F3134 360
5.4.3.5 Study Conversion Difficulty, F3135 360
5.4.3.6 Assemble Specifications Baseline Report, F3136 360
5.4.3.7 Coordinate Supplier Compliance, F3137 361
5.4.3.8 Accept New Requirement, F3138 361
5.4.3.9 Tailor Company Standards, F3139 361
5.4.3.10 Reject or Offer Alternative Document, F313A 361
5.4.3.11 Assess Customer Needs and Attitudes, F313B 361
5.4.3.12 Tailor Applicable Document, F313C 361
5.4.3.13 Study Impact of Compliance, F313D 361
5.4.3.14 Mark Up SOW and Top-Level Specification, F313E 361
5.4.3.15 Change Company Practice for Program Use, F313F 361
5.4.3.16 Assemble and Review Assessment Recommendations, F313G 361
5.4.3.17 Review Assessment Report, F313H 362
5.4.3.18 Negotiate With Customer, F313I 362
5.4.4 Team Tailoring 362
5.4.5 System Engineering Standards Relating to Requirements Analysis 362
5.5 Part II Specifications 364
5.5.1 The Part Situation 365
5.5.2 Specification Timing 365
5.5.3 Military Standards 366
5.5.4 Part II Specification Content Development 366
5.5.4.1 Outline Suggestion 366
5.5.4.2 Content Development Techniques 366
6 PART 6, REQUIREMENTS MANAGEMENT 368
6.1 Process Overview from a Management Perspective 370
6.1.1 Introduction 371
6.1.1.1 Overview 371
6.1.1.2 Total Quality Management 371
6.1.1.3 Buzzwords Forever 372
6.1.2 Program Preparation 372
6.1.2.1 Resource Overview 372
6.1.2.2 Specification Templates 373
6.1.2.3 Analytical Models 374
6.1.2.4 Model/Template Maps 374
6.1.2.5 Planned Writing Responsibilities 374
6.1.2.6 Preparation for Structured Analysis Work Product Capture 374
6.1.2.7 Applicable Document Action 374
6.1.2.8 Teaming Planning 375
6.1.2.9 Program Specification Library 376
6.1.2.9.1 Library Initiation 376
6.1.2.9.2 PSL Variations 376
6.1.2.9.3 Security 377
6.1.2.9.4 Availability 377
6.1.2.9.5 PSL Finances 377
6.1.2.9.6 Specification Standards Loading 377
6.1.2.9.7 Requirements Database Interface 377
6.1.2.9.8 Data Ownership 377
6.1.3 Program Implementation 377
6.1.3.1 Program Specifications Plan 377
6.1.3.1.1 Program-Unique Document Identification 378
6.1.3.1.2 Responsibility Assignment 378
6.1.3.1.3 Specification Scheduling and Statusing 379
6.1.3.1.4 Specification Baseline Identification 379
6.1.3.1.5 Baseline Definition Documentation 379
6.1.3.1.6 The Physical Baseline 379
6.1.3.1.7 Electronic Specification Library 379
6.1.3.1.8 Specification Change Management 379
6.1.3.2 Program Specification Standards Preparation 379
6.1.3.2.1 Responsibility and Content 379
6.1.3.2.2 Standards Availability 380
6.1.3.2.3 Multiple Standards Levels 380
6.1.3.3 Specification Tree Development 380
6.1.3.4 Principal Engineer Selection, Assignment, and Training 380
6.1.3.5 Program Specification Development Methods 381
6.1.3.6 Modularization of the Schedule 382
6.1.3.7 Regulating the Plunge 382
6.1.3.8 Selective Requirements Development 384
6.1.3.9 Requirements Risk Management 386
6.1.3.10 Process Controls 386
6.1.3.10.1 IPPT Meeting Structure 386
6.1.3.10.2 Requirements Traceability Audit 386
6.1.3.10.3 Status Tracking 386
6.1.3.10.4 Integration and Optimization Activity 386
6.1.3.11 Tailoring the Development Intensity 386
6.1.3.12 Development Data Package Concept 388
6.1.4 Program Closeout 390
6.2 Requirements Risk Management 392
6.2.1 Validation and Risk 393
6.2.2 The Validation Time Span 394
6.2.3 Avoiding a Null Solution Space 395
6.2.4 Validation Process Description 396
6.2.4.1 Overview 396
6.2.4.2 Initial Screening of the Requirements for Validation 397
6.2.4.3 Validation Intensity Selection 399
6.2.4.4 Formal Requirements Validation Management 400
6.2.4.5 Validation Through Risk Management 401
6.2.4.6 Technical Performance Measurement 401
6.2.4.7 Requirements Maturation Control 402
6.2.5 Validation Responsibility and Leadership 405
6.2.6 Validation Expectations 405
6.2.6.1 Requirements Necessity and Completeness 405
6.2.6.2 Requirements Value Credibility 406
6.2.6.3 Synthesizability 407
6.2.7 Validation Methods 408
6.2.7.1 Development Evaluation Testing (DET) 408
6.2.7.2 Analysis 409
6.2.7.3 Technology Demonstration 409
6.2.7.4 Examination 410
6.2.7.5 Combined Methods 410
6.2.7.6 Validation by Review 410
6.2.8 Product Representations 411
6.2.8.1 The Many Views of the Product 411
6.2.8.2 Representation Identification 412
6.2.8.3 Representation Management 413
6.2.8.4 Representations Documentation 413
6.2.8.5 Closing the Loop on Representations 414
6.2.9 Whole Program Phases 414
6.3 Requirements Value Management 415
6.3.1 Requirements Value Determination 416
6.3.2 TBD/TBR Management 416
6.3.3 Margin Management 417
6.3.3.1 Cost Margins 417
6.3.3.2 Schedule Margins 417
6.3.3.3 Characteristics Margins 417
6.3.3.4 Margin Consumption 418
6.3.4 Budgets 418
6.4 Requirements Integration 419
6.4.1 Who’s in Charge? 420
6.4.2 Item Process View 420
6.4.3 Aggregate Requirements Integration 420
6.4.3.1 Requirements Set Attributes 420
6.4.3.1.1 Consistency 420
6.4.3.1.2 Completeness 420
6.4.3.1.3 Minimized 421
6.4.3.1.4 Uniqueness 421
6.4.3.1.5 Balance 421
6.4.3.2 Individual Requirements Attributes 422
6.4.3.2.1 Traceability 422
6.4.3.2.2 Correctness of Style 422
6.4.3.2.3 Singleness of Purpose 422
6.4.3.2.4 Quantification 422
6.4.3.2.5 Verifiability 422
6.4.3.2.6 Unambiguity 422
6.4.3.2.7 Good Judgment and Good Sense 422
6.4.3.3 Margin Check 422
6.4.3.4 TPM Status Check 422
6.4.3.5 Specification Format Check 422
6.4.4 Engineering Specialty Integration Overview 422
6.4.5 Interface Requirements Analysis Integration 422
6.4.6 Environmental Requirements Analysis Integration 424
6.4.7 Process Requirements Integration 424
6.5 Interface Requirements Management 425
6.5.1 Internal Interface Control 426
6.5.2 Subcontractor Interface Control 426
6.5.3 Associate Contractors 426
6.5.3.1 Formal Contractual Coverage 426
6.5.3.2 Principal Integrating Contractor, SE& I Contractor, and IV&
6.5.3.3 Interface Control Working Group (ICWG) 426
6.5.3.4 Interface Control Document Control 426
6.5.4 Interface Integration Responsibility 427
6.5.5 Interface Audit 427
6.5.6 Some Nonstandard Interface Concepts 428
6.6 Requirements Verification Management 431
6.6.1 The Three-Step Process 432
6.6.2 The V Words 432
6.6.3 Verification Classes 432
6.6.4 Verification Methods 433
6.6.4.1 Test 433
6.6.4.2 Analysis 433
6.6.4.3 Demonstration 433
6.6.4.4 Examination. 433
6.6.4.5 Other Methods 433
6.6.4.5.1 Similarity 433
6.6.4.5.2 Simulation 434
6.6.5 Qualification Verification 434
6.6.5.1 Verification Requirements 434
6.6.5.2 Verification Plans and Procedures 434
6.6.5.3 Verification Implementation, Reports, and Audits 434
6.6.6 Acceptance Verification 434
6.6.7 System Test and Evaluation Verification 435
6.6.8 Management Matrices 435
6.7 Specification Development, Review, and Approval 437
6.7.1 Specification Development Controls 438
6.7.1.1 The Specification Tree 438
6.7.1.2 Responsibility Assignment 438
6.7.1.3 Process Controls 439
6.7.2 Specification Publishing 439
6.7.2.1 Formal Review Process 439
6.7.2.2 Peer Review 439
6.7.3 Specification Archiving, Distribution, and Access 439
6.7.3.1 Paper Methods 443
6.7.3.2 Networked Library 443
6.7.3.3 Web Page Library 443
6.7.4 Specification Change Management 443
6.7.4.1 Changes 443
6.7.4.2 Specification Change Notice 443
6.7.4.3 Proposed SCN 443
6.7.4.4 Approved SCN 445
6.7.4.5 Changed Pages 445
6.7.4.6 Change Numbering 445
6.7.4.7 Identification and Numbering of Changed Pages 445
6.7.4.8 Revisions 445
6.7.5 The Special Case of Interface Requirements Documentation 445
6.7.5.1 A Profusion of Document Names 445
6.7.5.2 Conditions of Use 446
6.7.5.3 Living and Dying Documents 447
6.7.5.4 Interface Definition and Document Organization 447
6.7.5.5 Interface Terminals and Media 448
6.7.5.6 System Environmental Interfaces 449
6.7.5.7 Transforming Lines into Requirements 450
6.7.5.8 Document Organization 451
6.7.5.8.1 Hardware ICD 451
6.7.5.8.2 Software Interface Requirements Specification MIL-STD-498 451
6.7.5.8.3 Mixed ICD 451
6.7.6 Electronic Style Guide 452
6.7.6.1 Documents of the Past 452
6.7.6.2 Database-Generated Specifications 452
6.7.6.3 The End of the Paper Specification 452
7 PART 7, COMPUTER APPLICATIONS 454
7.1 The Computer Tool Infrastructure 456
7.1.1 Why Have We Waited So Long? 457
7.1.2 Evolution of Methods 457
7.1.3 The Computer Tool Environment 458
7.1.4 Requirements and Specifications Electronic Environment 458
7.1.5 Networking and Workgroup Computing 459
7.1.6 A Basic Requirements Database 460
7.1.7 Traceability Hooks 461
7.1.8 Verification Tracking Tool 461
7.1.9 Requirements Management Data Fields 462
7.1.10 External Model Hooks 463
7.1.11 Traceability to Process 463
7.1.12 Data Integrity 465
7.2 Computer Tools for Requirements Analysis 466
7.2.1 A Little history 467
7.2.2 Buy or Build 467
7.2.3 Available Tools and Their Features 467
7.2.3.1 CORE 468
7.2.3.2 DOORS 468
7.2.3.3 RDD-100 468
7.2.3.4 SLATE 468
7.2.3.5 RTM 468
7.2.3.6 Other Requirements Tools 468
7.2.3.7 Software Modeling Tools 468
7.2.4 Features not Generally Supported 468
7.2.4.1 Design Constraints Identification 468
7.2.4.2 Tool Linkage 468
7.2.4.3 Primitive Capture and Numerical Content 469
7.2.5 Implementation Suggestions 469
7.2.5.1 Overcoming Use Difficulties 469
7.2.5.2 Networking 469
8 PART 8, CLOSING 470
8.1 Where Have We Been? 472
8.1.1 What Is the Essence of Our Story? 473
8.1.1.1 Teamwork and Concurrency 473
8.1.1.2 Development Directionality 473
8.1.1.3 Multiple Requirements Analysis Strategies 473
8.1.1.4 Demand-Driven Requirements Analysis 473
8.1.1.5 Progressive Requirements Writing 474
8.1.1.6 The Computers are Coming! 474
8.1.2 Overcoming Impediments to SRA Success 474
Acronyms 476
Index 478