Managing Technical Debt: Reducing Friction in Software Development

Over time, technical debt affects virtually every significant software project. As software systems evolve, earlier design or code decisions prove to be ? not quite right, ? gradually becoming impediments that slow down the evolution of the system, or even grind it to a halt. Most software practitioners have experienced this phenomenon, but many feel helpless to address it. In this guide, three leading software engineering experts introduce empirically validated principles and practices for managing and mitigating technical debt in any software system. Using real-life examples, the authors explain the forms of technical debt that afflict software-intensive systems, their root causes, and their impacts. Next, they introduce a palette of proven approaches, strategies, methods, and tools for:

• Identifying sources of technical debt in any software system
• Assessing the magnitude of technical debt
• Limiting the introduction of technical debt in the first place
• Reducing the impact of technical debt over time

As software systems mature, the challenge of technical debt has grown, and it has become increasingly urgent for software professionals and their managers to address it head-on. Managing Technical Debt shows them how.

Foreword        xiii
Preface        xv
Part I: Exploring the Technical Debt Landscape        1
Chapter 1: Friction in Software Development        3
The Promise of Managing Technical Debt        3
Technical Debt A-B-C        5
Examples of Technical Debt        6
Your Own Story About Technical Debt?         11
Who Is This Book For?         12
Principles of Technical Debt Management        13
Navigating the Concepts of the Book        14
What Can You Do Today?         16
For Further Reading        17
Chapter 2: What Is Technical Debt?         19
Mapping the Territory        19
The Technical Debt Landscape        20
Technical Debt Items: Artifacts, Causes, and Consequences        22
Principal and Interest        24
Cost and Value        27
Potential Debt versus Actual Debt        32
The Technical Debt Timeline        33
What Can You Do Today?         35
For Further Reading        35
Chapter 3: Moons of Saturn– The Crucial Role of Context        37
“ It Depends… ”         37
Three Case Studies: Moons of Saturn        39
Technical Debt in Context        44
What Can You Do Today?         48
For Further Reading        48

Part II: Analyzing Technical Debt        49
Chapter 4: Recognizing Technical Debt        51
Where Does It Hurt?         51
What Are the Visible Consequences of Technical Debt?         54
Writing a Technical Debt Description        55
Understanding the Business Context for Assessing Technical Debt        58
Assessing Artifacts Across the Technical Debt Landscape        60
What Can You Do Today?         63
For Further Reading        64
Chapter 5: Technical Debt and the Source Code        65
Looking for the Magic Wand        65
Understand Key Business Goals        68
Identify Questions About the Source Code        70
Define the Observable Measurement Criteria        72
Select and Apply an Analysis Tool        75
Document the Technical Debt Items        76
Then Iterate        78
What Happens Next?         79
What Can You Do Today?         80
For Further Reading        81
Chapter 6: Technical Debt and Architecture        83
Beyond the Code        83
Ask the Designers        86
Examine the Architecture        89
Examine the Code to Get Insight into the Architecture        93
The Case of Technical Debt in the Architecture of Phoebe        94
What Can You Do Today?         101
For Further Reading        101
Chapter 7: Technical Debt and Production        103
Beyond the Architecture, the Design, and the Code        103
Build and Integration Debt        106
Testing Debt        109
Infrastructure Debt        110
The Case of Technical Debt in the Production of Phoebe        110
What Can You Do Today?         113
For Further Reading        113

Part III: Deciding What Technical Debt to Fix        115
Chapter 8: Costing the Technical Debt        117
Shining an Economic Spotlight on Technical Debt        117
Refine the Technical Debt Description        119
Calculate the Cost of Remediation        121
Calculate the Recurring Interest        122
Compare Cost and Benefit        123
Manage Technical Debt Items Collectively        127
What Can You Do Today?         129
For Further Reading        130
Chapter 9: Servicing the Technical Debt        131
Weighing the Costs and Benefits        131
Paths for Servicing Technical Debt        136
The Release Pipeline        142
The Business Case for Technical Debt as an Investment        143
What Can You Do Today?         146
For Further Reading        147

Part IV: Managing Technical Debt Tactically and Strategically        149
Chapter 10: What Causes Technical Debt?         151
The Perplexing Art of Identifying What Causes Debt        151
The Roots of Technical Debt        153
What Causes Technical Debt?         154
Causes Rooted in the Business        155
Causes Arising from Change in Context        157
Causes Associated with the Development Process        159
Causes Arising from People and Team        162
To Conclude        165
What Can You Do Today?         165
For Further Reading        166
Chapter 11: Technical Debt Credit Check        167
Identifying Causes: Technical Debt Credit Check        167
Four Focus Areas for Understanding the State of a Project        170
Diagnosing the Causes of Technical Debt in Phoebe        172
Diagnosing the Causes of Technical Debt in Tethys        174
What Can You Do Today?         177
For Further Reading        178
Chapter 12: Avoiding Unintentional Debt        179
Software Engineering in a Nutshell        179
Code Quality and Unintentional Technical Debt        180
Architecture, Production, and Unintentional Technical Debt        185
What Can You Do Today?         193
For Further Reading        193
Chapter 13: Living with Your Technical Debt        195
Your Technical Debt Toolbox        195
On the Three Moons of Saturn…         201
Technical Debt and Software Development        204
Finale        205
Glossary        207
References        209
Index        217