Executable Specifications with Scrum: A Practical Guide to Agile Requirements Discovery

Most books about specifications still assume that requirements can be known up front and won’t change much during your project. In today’s “real world,” however, you must specify and build software in the face of high and continuing uncertainty. Scrum and other agile methods have evolved to reflect this reality. Now, there’s a complete guide to specifying software in agile environments when prerequisites are unclear, requirements are difficult to grasp, and anything about your project could change. Long-time agile coach and enterprise architect Mario Cardinal shows how to create executable specifications and use them to test software behavior against requirements. Cardinal shows how to trawl requirements incrementally, step-by-step, using a vision-centric and emergent iterative practice that is designed for agility. Writing for analysts, architects, developers, and managers, Cardinal makes a strong case for the iterative discovery of requirements. Then, he moves from theory to practice, fully explaining the technical mechanisms and empirical techniques you need to gain full value from executable specifications. You’ll learn to connect specifications with software under construction, link requirements to architecture, and automate requirements verification within the Scrum framework. Above all, Cardinal will help you solve the paramount challenge of software development: not only to solve the problem right, but also to solve the right problem. You will learn how to • Establish more effective agile roles for analysts and architects • Integrate and simplify the best techniques from FIT, ATDD, and BDD • Identify “core certainties” on which your project team should rely to ensure requirements discovery • Manage uncertainty by discovering stakeholder desires through short feedback loops • Specify as you go while writing small chunks of requirements • Use storyboarding and paper prototyping to improve conversations with stakeholders • Express stakeholder desires that are requirements with user stories • Refine your user stories, and plan more effective Scrum sprints • Confirm user stories by scripting behaviors with scenarios • Transform scenarios into automated tests that easily confirm your software’s expected behavior as designs emerge and specifications evolve • Ensure higher-quality software by specifying nonfunctional requirements

Table of Contents:
Preface xvi Chapter 1 Solving the Right Problem 1 Distinguishing the Requirements from the Solution 4 Recognizing the Impact of Uncertainty 5 Tackling Uncertainty 7 Summary 10 References 10 Chapter 2 Relying on a Stable Foundation 13 Defining What Will Hardly Change 14 Creating a Healthy Team 14 Requiring the Involvement of All Stakeholders 16 Expressing a Shared Vision 17 Distinguishing a Meaningful Common Goal 20 Identifying a Set of High-Level Features 21 Validating the “Can-Exist” Assumption 22 Summary 23 References 23 Chapter 3 Discovering Through Short Feedback Loops and Stakeholders’ Desirements 25 Applying the Trial-and-Error Method 25 Using Short Feedback Loops 29 Targeting Feedback Along the Expected Benefits 31 Focusing on the Stakeholders’ Desirements 31 Summary 34 References 34 Chapter 4 Expressing Desirements with User Stories 35 Describing Desirements by Using User Stories 35 Discovering Desirements by Exploring Roles and Benefits 38 Establishing a Ubiquitous Language 40 Recording Desirements by Using a Product Backlog 41 Summary 43 References 44 Chapter 5 Refining User Stories by Grooming the Product Backlog 45 Managing the Product Backlog 46 Collaborating to Groom the Product Backlog 48 Ranking User Stories with a Dot Voting Method 49 Illustrating User Stories with Storyboards 52 Sizing User Stories Using Comparison 56 Splitting User Stories Along Business Values 60 Tracking User Stories with a Collaboration Board 62 Delivering a Coherent Set of User Stories 68 Planning Work with User Stories 70 Summary 71 References 72 Chapter 6 Confirming User Stories with Scenarios 73 Scripting User Stories with Scenarios 74 Expressing Scenarios with Formality 76 Scripting Scenarios Using the FIT Tabular Format 77 Scripting Scenarios Using Given-When-Then Syntax 79 Choosing Between FIT Tabular Format or Given-When-Then Syntax 80 Formalizing a Ubiquitous Language 81 Splitting Scenarios into Commands or Queries 83 Confirming Collaboratively in a Two-Step Process 85 Removing Technical Considerations from Scenarios 89 Evolving Scenarios from Sprint to Sprint 91 Organizing Scenarios by Feature 92 Documenting Scenarios by Feature 93 Avoiding Duplication and Merging Conflicts 94 Summary 95 References 96 Chapter 7 Automating Confirmation with Acceptance Tests 97 Evolving Scenarios into Acceptance Tests 98 Automating Scenarios Using the Red-Green-Refactor Cycle 101 Translating the Scenario into an Acceptance Test 104 Transposing Using an Internal DSL 104 Creating a Test 107 Coding the DSL into the Newly Created Test 108 Connecting the Newly Created Test with the Interface 110 Exercising the Interface 112 Chaining Context Between the Steps of the Scenario 113 Making the Test Fail 114 Implementing the Interface 115 Replacing Unit Testing with Context-Specification Testing 116 Making the Test Pass 117 Evolving the Acceptance Test 117 Running Acceptance Tests Side-by-Side with Continuous Integration 118 Enhancing Scenarios with Test Results 119 Summary 121 References 122 Chapter 8 Addressing Nonfunctional Requirements 123 Improving External Quality Using Restrictions 125 Translating Nonfunctional Requirements into Restrictions 127 Reducing the Functional Scope to a Single Scenario 129 Setting Measurable Quality Objectives 131 Testing Restrictions with Proven Practices 135 Ensuring Internal Quality Using Sound Engineering Practices 137 Improving Software Construction with Explicit Practices 137 Mastering Practices with Collaborative Construction 140 Summary 142 References 143 Chapter 9 Conclusion 145 Recapitulating the Book 146 Summarizing the Process 148 Drawing Attention to Individual Roles 149 Glossary 153 Index 159

About the Author :
Known for many years as an agile coach specialized in software architecture, Mario Cardinal is the co-founder of Slingboards Lab, a young start-up that brings sticky notes to smartphones, tablets and the web for empowering teams to better collaborate. A visionary and an entrepreneur, he likes to seize the opportunities that emerge from the unexpected. His friends like to describe him as someone who can extract the essence of a complicated situation, sort out the core ideas from the incidental distractions, and provide a summary that is easy to understand. For the ninth consecutive year, he has received the Most Valuable Professional (MVP) award from Microsoft. MVP status is awarded to credible technology experts who are among the very best community members willing to share their experience to help others realize their potential.