Software Architecture Metrics: Case Studies to Improve the Quality of Your Architecture

Preface
    What Will You Learn?
    Who This Book Is For
    Conventions Used in This Book
    O’Reilly Online Learning
    How to Contact Us
    Acknowledgments
        Christian Ciceri
        Dave Farley
        Neal Ford
        Andrew Harmel-Law
        Michael Keeling
        Carola Lilienthal
        João Rosa
        Alexander von Zitzewitz
        Rene Weiss
        Eoin Woods
1. Four Key Metrics Unleashed
    Definition and Instrumentation
    Refactoring Your Mental Model
        Pipelines as Your First Port of Call
        Locating Your Instrumentation Points
    Capture and Calculation
    Display and Understanding
        Target Audience
        Visualization
        Front Page
    Discussions and Understanding
    Ownership and Improvement
    Conclusion
2. The Fitness Function Testing Pyramid: An Analogy for Architectural Tests and Metrics
    Fitness Functions and Metrics
        Fitness Functions: Test Coverage
        Fitness Functions: Integration Tests with Network Latency
    Introduction to Fitness Function Categories
        Mandatory Fitness Function Categories
        Optional Fitness Function Categories
        Fitness Function Categories: Catalog Overview
    The Testing Pyramid
    The Fitness Function Testing Pyramid
        The Top Layer
        The Middle Layer
        The Bottom Layer
    Examples and Their Full Categorization
    Fully Categorizing Top-Layer Examples
    Developing Your Fitness Functions and Metrics
    Conclusion
3. Evolutionary Architecture: Guiding Architecture with Testability and Deployability
    The Importance of Learning and Discovery
    The Tools of Sustainable Change
    Testability: Creating High-Quality Systems
    Deployability: Scaling Development of Our Systems
    Conclusion
4. Improve Your Architecture with the Modularity Maturity Index
    Technical Debt
    Origination of Technical Debt
    Assessment with the MMI
    Modularity
    Hierarchy
    Pattern Consistency
    Calculating the MMI
    Architecture Review to Determine the MMI
    Conclusion
5. Private Builds and Metrics: Tools for Surviving DevOps Transitions
    Key Terms
        CI/CD
        DevOps
    The “Ownership Shift”
    Empowering the Local Environment Again
    The Private Build
    Case Study: The Unstable Trunk
        Bug A1
        Bug A2
        Bug A3
        Bug A4
    Case Study: The Blocked Consultant
    Metrics
        Time to Feedback
        Evitable Integration Issues in the Deployed Application per Iteration
        Time Spent Restoring Trunk Stability per Iteration
        The Cost of Private Builds
    Metrics in Practice
        High Time to Feedback, High Evitable Integration Issues, Low Time to Trunk Stability
        Low Time to Feedback, High Evitable Integration Issues, Low Time to Trunk Stability
        High Time to Feedback, Low Evitable Integration Issues, Low Time to Trunk Stability
        Low Evitable Integration Issues and High Time to Trunk Stability
    Conclusion
6. Scaling an Organization: The Central Role of Software Architecture
    YourFinFreedom Breaks the Monolith
    Implementing a Distributed Big Ball of Mud
    Seeking Direction
    From Best Effort to Intentional Effort
    Increasing Software Architecture Intentionality, Guided by Metrics
    Managing Expectations with Communication
    Learning and Evolving the Architecture
    And What About Anna?
    Conclusion
7. The Role of Measurement in Software Architecture
    Adding Measurement to Software Architecture
    Measurement Approaches
        Runtime Measurement of Applications and Infrastructure
        Software Analysis
        Design Analysis
        Estimates and Models
        Fitness Functions
    Measuring System Qualities
        Performance
        Scalability
        Availability
        Security
    Getting Started
    Hypothetical Case Study
    Pitfalls
    Conclusion
8. Progressing from Metrics to Engineering
    The Path to Fitness Functions
    From Metrics to Engineering
    Automation Operationalizes Metrics
    Case Study: Coupling
    Case Study: Zero-Day Security Check
    Case Study: Fidelity Fitness Functions
    Conclusion
9. Using Software Metrics to Ensure Maintainability
    The Case for Using Metrics
        Entropy Kills Software
        The Toxicity of Cyclic Dependencies
        How Metrics Can Help
    Why Are Metrics Not More Widely Used?
    Tools to Gather Metrics
    Useful Metrics
        Metrics to Measure Coupling and Structural Erosion
        Metrics to Measure Size and Complexity
        Change History Metrics
        Other Useful Metrics
    Architectural Fitness Functions
    How to Track Metrics over Time
    A Few Golden Rules for Better Software
    Conclusion
10. Measure the Unknown with the Goal-Question-Metric Approach
    The Goal-Question-Metric Approach
        Create a GQM Tree
        Prioritize Metrics and Devise a Data Collection Strategy
    Case Study: The Team That Learned to See the Future
        System Context
        Incident #1: Too Many Requests to the Foo Service
        Incident #2: Seeing the Future
        Reflection
    Run a GQM Workshop
        Workshop Summary
        Workshop Steps
        Facilitation Guidelines and Hints
    Conclusion
Index
About the Authors