Estimating Software-Intensive Systems: Projects, Products, and Processes

949 Pages·2005·18.099 MB·English

by  Stutzke, Richard D

Estimating
Software-Intensive
Systems
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Estimating
Software-Intensive
Systems
Projects, Products, and Processes
Richard D. Stutzke
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The SEI Series in Software Engineering
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Contents
Preface.................................................................................................................xv
Acknowledgments.........................................................................................xxii
About the Author...........................................................................................xxiv
Part 1: The Essentials....................................................................................1
Chapter 1: Introduction ............................................................................................3
1.1 Reasons to Estimate and Measure .........................................................4
1.2 Specific Quantities to Estimate and Measure .......................................7
1.3 The Nature of Estimation ........................................................................8
1.4 Unprecedented Systems ........................................................................15
1.5 Why Software Is Especially Hard to Estimate ....................................18
1.6 APractical Approach .............................................................................20
1.7 Recommended Reading ........................................................................23
1.8 Summary .................................................................................................23
Chapter 2: Planning a Warehouse Inventory System .......................................27
2.1 Warehouse Inventory Management System ......................................28
2.2 Recording the Information ...................................................................30
2.3 Discussion of the Example ....................................................................35
2.4 Doing Better: APlanning Workbook ...................................................44
2.5 Recommended Reading ........................................................................47
2.6 Summary .................................................................................................47
Chapter 3: ABasic Estimating Process: The Linear Method............................49
3.1 Criteria for “Good” Estimates...............................................................50
3.2 Types of Resources..................................................................................53
3.3 Proxy-Based Estimation.........................................................................54
3.4 The Linear Method: ASimple Process.................................................57
3.5 Using the Linear Method.......................................................................64
3.6 Documenting Your Estimates...............................................................69
v
vi Contents
3.7 Standard Forms.......................................................................................73
3.8 Managing Your Information.................................................................76
3.9 Recommended Reading.........................................................................78
3.10 Summary................................................................................................79
Chapter 4: Measurement and Estimation ...........................................................81
4.1 Reasons to Measure ...............................................................................82
4.2 Measuring Size and Productivity (Direct and Indirect Measures) ..83
4.3 Criteria for “Good” Measures ..............................................................91
4.4 Operational Definitions .........................................................................93
4.5 Choosing Useful Measures ..................................................................97
4.6 Recommended Reading ........................................................................99
4.7 Summary ...............................................................................................101
Chapter 5: Estimating Techniques ......................................................................103
5.1 Expert Judgment: The Delphi Technique ..........................................104
5.2 Additive and Multiplicative Analogies .............................................108
5.3 Program Evaluation and Review Technique (PERT) .......................112
5.4 An Example: Using PERT Values .......................................................115
5.5 Using the PERT Values to Estimate Risk Reserve ............................117
5.6 Algorithmic Analogy Estimation .......................................................120
5.7 Recommended Reading ......................................................................123
5.8 Summary ..............................................................................................124
Chapter 6: Estimating Annual Maintenance Costs .........................................125
6.1 The Maintenance Process ....................................................................125
6.2 Building the Estimation Model ..........................................................135
6.3 Calibrating the Model .........................................................................141
6.4 Tracking and Updating .......................................................................142
6.5 Improving the Estimation Model .......................................................144
6.6 Recommended Reading ......................................................................149
6.7 Summary ...............................................................................................151
Part 2: The Details.....................................................................................153
Chapter 7: Preparing to Estimate (Precursors of Estimation) ........................155
7.1 The Precursors of Estimation ..............................................................156
7.2 How to Understand the Overall Job: The Key Diagrams ...............157
7.3 The Operational Concept ....................................................................159
Contents vii
7.4 Identifying Products and Services .....................................................162
7.5 Product Requirements .........................................................................165
7.6 Product Architecture ...........................................................................171
7.7 Project Goals and Constraints ............................................................174
7.8 Recommended Reading ......................................................................177
7.9 Summary ...............................................................................................177
Chapter 8: Estimating Software Size: The Basics ............................................179
8.1 The Sizing Process ................................................................................180
8.2 Example: Using the Operational Concept ........................................186
8.3 Sizing Hardware ..................................................................................191
8.4 Accounting for Size Growth and Volatility ......................................194
8.5 Tracking Size .........................................................................................196
8.6 Implementation Guidance ..................................................................203
8.7 Recommended Reading ......................................................................205
8.8 Summary ...............................................................................................205
Chapter 9: Estimating Software Size: The Details ..........................................207
9.1 Requirements ........................................................................................208
9.2 UML-Based Sizing and Use Case Points ...........................................209
9.3 Application Points ...............................................................................213
9.4 Web Objects and Internet Points ........................................................216
9.5 Function Points .....................................................................................217
9.6 Simplified Ways to Count Function Points .......................................228
9.7 Object-Oriented Size Measures ..........................................................238
9.8 Defining Source Lines of Code (SLOC) .............................................239
9.9 Estimating New Code .........................................................................244
9.10 Sizing Reused Source Code ..............................................................251
9.11 “Sizing” Commercial Off-the-Shelf Software Components .........264
9.12 The COCOTS Model ..........................................................................265
9.13 Recommended Reading ....................................................................267
9.14 Summary .............................................................................................270
Chapter 10: Production Processes (Project Life Cycles) .................................273
10.1 Elements of a Project Life Cycle Model ...........................................274
10.2 The Spectrum of Software Life Cycles ............................................275
10.3 Choosing an Appropriate Project Life Cycle ..................................287
10.4 Extending the Basic Development Life Cycle Models ..................288
10.5 Production and Delivery Activities .................................................299
10.6 Recommended Reading ....................................................................304
10.7 Summary .............................................................................................305
viii Contents
Chapter 11: Bottom-Up Estimating and Scheduling .......................................307
11.1 Summary of the Process ....................................................................308
11.2 The Work Breakdown Structure .......................................................310
11.3 Creating Your WBS ............................................................................315
11.4 Scheduling ..........................................................................................320
11.5 Building the Network: Cards on the Wall Method ........................332
11.6 Recommended Reading ....................................................................337
11.7 Summary .............................................................................................338
Chapter 12: Top-Down Estimating and Allocation .........................................341
12.1 Relating Effort, Duration, and Staffing ...........................................342
12.2 Planned Versus Actual Availability .................................................346
12.3 Schedule Compression ......................................................................349
12.4 Allocating Effort and Time ................................................................352
12.5 Some Examples ..................................................................................369
12.6 Recommended Reading ....................................................................373
12.7 Summary .............................................................................................373
Chapter 13: Parametric Models ...........................................................................377
13.1 Types of Parametric Models .............................................................377
13.2 Core Effort and Schedule ..................................................................378
13.3 ASimple Parametric Model ..............................................................380
13.4 Adding Missing Phases and Activities ............................................382
13.5 Adjusting for Different Characteristics ...........................................383
13.6 Handling Size, Cost, and Schedule Constraints ............................387
13.7 Evaluating a Hardware/Software Trade ........................................389
13.8 Calibrating Parametric Models ........................................................391
13.9 Parametric Models for Hardware Costs .........................................401
13.10 Selecting an Automated Estimation Tool ......................................403
13.11 Helping Nonestimators Provide Good Parameter Values ..........405
13.12 Recommended Reading ..................................................................417
13.13 Summary ...........................................................................................418
Chapter 14: Estimating Risk Reserves ...............................................................421
14.1 Concepts ..............................................................................................422
14.2 The Risk Management Process .........................................................424
14.3 Identifying Risks and Mitigation Actions .......................................426
14.4 Analyzing and Prioritizing Risks: Risk Impact ..............................433
14.5 Calculating the Risk Reserve ............................................................438
14.6 Planning: Deciding to Defer Mitigation Tasks ...............................440
14.7 Tracking and Updating .....................................................................443
Contents ix
14.8 Other Approaches ..............................................................................443
14.9 Recommended Reading ....................................................................444
14.10 Summary ...........................................................................................445
Chapter 15: Calculating Cost and Price: The Basics ........................................447
15.1 Direct and Indirect Costs ...................................................................448
15.2 Calculating Direct Costs ....................................................................449
15.3 Calculating Indirect Costs .................................................................451
15.4 Profit and the “Fee Rate” ...................................................................454
15.5 Calculating the Loaded Cost ............................................................454
15.6 Management Reserves ......................................................................455
15.7 Cash Flow and Interest Costs ...........................................................456
15.8 Opportunity Cost ...............................................................................458
15.9 Determining the Selling Price for a Product6 .................................459
15.10 Evaluating the Total Ownership Cost ...........................................461
15.11 Evaluating a Product or Project ......................................................464
15.12 Reducing the Cost or Price ..............................................................466
15.13 The Need for Multiple Models .......................................................470
15.14 Recommended Reading ..................................................................471
15.15 Summary ...........................................................................................472
Part 3: Closing the Feedback Loop........................................................475
Chapter 16: Collecting Data: Basics ...................................................................477
16.1 Why Should You Even Collect Historical Data? ............................477
16.2 Collecting Data ...................................................................................478
16.3 Data Collection Templates ................................................................479
16.4 Automating Data Collection and Analysis .....................................500
16.5 Collecting Effort and Cost Data ......................................................500
16.6 Recommended Reading ....................................................................502
16.7 Summary .............................................................................................503
Chapter 17: Tracking Status .................................................................................505
17.1 Assessing Status .................................................................................506
17.2 Tracking Test Status ...........................................................................507
17.3 Tracking Size and Productivity ........................................................513
17.4 Tracking Size with Error Bars ...........................................................516
17.5 Trendlines ............................................................................................517
17.6 Regression Fitting ..............................................................................519
17.7 Other Ways to Detect Trouble ...........................................................521
17.8 Recommended Reading ....................................................................523
17.9 Summary .............................................................................................523