Agile Estimating and Planning / Edition 1

by Mike Cohn

Overview

Detailed, Proven Techniques for Estimating and Planning Any Agile Project

Agile Estimating and Planning is the definitive, practical guide to estimating and planning agile projects. In this book, Agile Alliance cofounder Mike Cohn discusses the philosophy of agile estimating and planning and shows you exactly how to get the job done, with real-world examples and case studies.

Concepts are clearly illustrated and readers are guided, step by step, toward how to answer the following questions: What will we build? How big will it be? When must it be done? How much can I really complete by then? You will first learn what makes a good plan-and then what makes it agile.

Using the techniques in Agile Estimating and Planning, you can stay agile from start to finish, saving time, conserving resources, and accomplishing more. Highlights include:

• Why conventional prescriptive planning fails and why agile planning works

• How to estimate feature size using story points and ideal days—and when to use each

• How and when to re-estimate

• How to prioritize features using both financial and nonfinancial approaches

• How to split large features into smaller, more manageable ones

• How to plan iterations and predict your team's initial rate of progress

• How to schedule projects that have unusually high uncertainty or schedule-related risk

• How to estimate projects that will be worked on by multiple teams

Agile Estimating and Planning supports any agile, semiagile, or iterative process, including Scrum, XP, Feature-Driven Development, Crystal, Adaptive Software Development, DSDM, Unified Process, and many more. It will be an indispensable resource for every development manager, team leader, and team member.

Product Details

ISBN-13:	9780131479418
Publisher:	Pearson Education
Publication date:	11/01/2005
Series:	Robert C. Martin Series
Edition description:	New Edition
Pages:	368
Product dimensions:	7.00(w) x 9.15(h) x 0.75(d)

About the Author

Mike Cohn is the founder of Mountain Goat Software, a process and project management consultancy and training firm. With more than twenty years of experience, Mike has been a technology executive in companies ranging from start-ups to Fortune 40s, and is a founding member of the Agile Alliance. He frequently contributes to industry-related magazines and presents regularly at conferences. He is the author of User Stories Applied (Addison-Wesley, 2004).

Read an Excerpt

This book could have been called Estimating and Planning Agile Projects. Instead, it's called Agile Estimating and Planning. The difference may appear subtle, but it's not. The title makes it clear that the estimating and planning processes must themselves be agile. Without agile estimating and planning, we cannot have agile projects.

The book is mostly about planning, which I view as answering the question of "What should we build and by when?" However, to answer questions about planning we must also address questions of estimating ("How big is this?") and scheduling ("When will this be done?" and "How much can I have by then?").

This book is organized in seven parts and twenty-three chapters. Each chapter ends with a summary of key points and with a set of discussion questions. Because estimating and planning are meant to be whole-team activities, one of the ways I hope this book will be read is by teams who meet perhaps weekly to discuss what they've read and the questions at the end of each chapter. Because agile software development is popular worldwide, I have tried to avoid writing an overly United States-centric book. To that end, I have used the universal currency symbol, writing amounts such as ¤500 instead of perhaps $500 or €500 and so on.

Part I describes why planning is important, the problems we often encounter, and the goals of an agile approach. Chapter 1 begins the book by describing the purpose of planning, what makes a good plan, and what makes planning agile. The most important reasons why traditional approaches to estimating and planning lead to unsatisfactory results are described in Chapter 2. Finally, Chapter 3 begins with a briefrecap of what agility means and then describes the high-level approach to agile estimating and planning taken by the rest of this book.

The second part introduces a main tenet of estimating, that estimates of size and duration should be kept separate. Chapters 4 and 5 introduce story points and ideal days, two units appropriate for estimating the size of the features to be developed. Chapter 6 describes techniques for estimating in story points and ideal days, and includes a description of planning poker. Chapter 7 describes when and how to re-estimate, and Chapter 8 offers advice on choosing between story points and ideal days.

Part III, "Planning for Value," offers advice on how a project team can make sure they are building the best possible product. Chapter 9 describes the mix of factors that need to be considered when prioritizing features. Chapter 10 presents an approach for modeling the financial return from a feature or feature set and how to compare financial returns so that the team works on the most valuable items first. Chapter 11 includes advice on how to assess and then prioritize the desirability of features to a product's users. Chapter 12 concludes this part with advice on how to split large features into smaller, more manageable ones.

In Part IV, we shift our attention and focus on questions around scheduling a project. Chapter 13 begins by looking at the steps involved in scheduling a relatively simple, single-team project. Next, Chapter 14 looks at how to plan an iteration. Chapters 15 and 16 look at how to select an appropriate iteration length for the project and how to estimate a team's initial rate of progress. Chapter 17 looks in detail at how to schedule a project with either a high amount of uncertainty or a greater implication to being wrong about the schedule. This part concludes with Chapter 18, which describes the additional steps necessary in estimating and planning a project being worked on by multiple teams.

Once a plan has been established, it must be communicated to the rest of the organization and the team's progress against it monitored. These are the topics of the three chapters of Part V. Chapter 19 looks specifically at monitoring the release plan, while Chapter 20 looks at monitoring the iteration plan. The final chapter in this part, Chapter 21, deals specifically with communicating about the plan and progress toward it.

Chapter 22 is the lone chapter in Part VI. This chapter argues the case for why agile estimating and planning work and stands as a counterpart to Chapter 2, which describes why traditional approaches fail so often.

Part VII, the final part, includes only one chapter. Chapter 23 is an extended case study that reasserts the main points of this book but does so in a fictional setting.

Table of Contents

About the Author xvii Foreword by Robert C. Martin xix Foreword by Jim Highsmith xxi Foreword by Gabrielle Benefield xxv Acknowledgments xxvii Introduction xxix Part I: The Problem and the Goal 1 Chapter 1: The Purpose of Planning 3

Why Do It? 5

What Makes a Good Plan? 8

What Makes Planning Agile? 9

Summary 10

Discussion Questions 10

Chapter 2: Why Planning Fails 11

Planning Is by Activity Rather Than Feature 12

Multitasking Causes Further Delays 15

Features Are Not Developed by Priority 17

We Ignore Uncertainty 17

Estimates Become Commitments 18

Summary 18

Discussion Questions 19

Chapter 3: An Agile Approach 21

An Agile Approach to Projects 23

An Agile Approach to Planning 27

Summary 31

Discussion Questions 32

Part II: Estimating Size 33 Chapter 4: Estimating Size with Story Points 35

Story Points Are Relative 36

Velocity 38

Summary 40

Discussion Questions 41

Chapter 5: Estimating in Ideal Days 43

Ideal Time and Software Development 44

Ideal Days as a Measure of Size 46

One Estimate, Not Many 46

Summary 47

Discussion Questions 47

Chapter 6: Techniques for Estimating 49

Estimates Are Shared 51

The Estimation Scale 52

Deriving an Estimate 54

Planning Poker 56

Why Planning Poker Works 59

Summary 60

Discussion Questions 60

Chapter 7: Re-Estimating 61

Introducing the SwimStats Website 61

When Not to Re-Estimate 62

When to Re-Estimate 64

Re-Estimating Partially Completed Stories 66

The Purpose of Re-Estimating 67

Summary 67

Discussion Questions 67

Chapter 8: Choosing between Story Points and Ideal Days 69

Considerations Favoring Story Points 69

Considerations Favoring Ideal Days 72

Recommendation 73

Summary 74

Discussion Questions 75

Part III: Planning for Value 77 Chapter 9: Prioritizing Themes 79

Factors in Prioritization 80

Combining the Four Factors 86

Some Examples 86

Summary 88

Discussion Questions 89

Chapter 10: Financial Prioritization 91

Sources of Return 93

An Example: WebPayroll 96

Financial Measures 102

Comparing Returns 108

Summary 109

Discussion Questions 109

Chapter 11: Prioritizing Desirability 111

Kano Model of Customer Satisfaction 112

Relative Weighting: Another Approach 117

Summary 119

Discussion Questions 120

Chapter 12: Splitting User Stories 121

When to Split a User Story 121

Splitting across Data Boundaries 122

Splitting on Operational Boundaries 124

Removing Cross-Cutting Concerns 125

Don't Meet Performance Constraints 126

Split Stories of Mixed Priority 127

Don't Split a Story into Tasks 127

Avoid the Temptation of Related Changes 128

Combining Stories 128

Summary 129

Discussion Questions 129

Part IV: Scheduling 131 Chapter 13: Release Planning Essentials 133

The Release Plan 134

Updating the Release Plan 138

An Example 139

Summary 142

Discussion Questions 143

Chapter 14: Iteration Planning 145

Tasks Are Not Allocated During Iteration Planning 147

How Iteration and Release Planning Differ 148

Velocity-Driven Iteration Planning 149

Commitment-Driven Iteration Planning 158

My Recommendation 162

Relating Task Estimates to Story Points 163

Summary 165

Discussion Questions 166

Chapter 15: Selecting an Iteration Length 167

Factors in Selecting an Iteration Length 167

Making a Decision 171

Two Case Studies 173

Summary 175

Discussion Questions 176

Chapter 16: Estimating Velocity 177

Use Historical Values 178

Run an Iteration 179

Make a Forecast 181

Which Approach Should I Use? 185

Summary 186

Discussion Questions 186

Chapter 17: Buffering Plans for Uncertainty 187

Feature Buffers 188

Schedule Buffers 189

Combining Buffers 198

A Schedule Buffer Is Not Padding 199

Some Caveats 199

Summary 200

Discussion Questions 201

Chapter 18: Planning the Multiple-Team Project 203

Establishing a Common Basis for Estimates 204

Adding Detail to User Stories Sooner 205

Lookahead Planning 206

Incorporating Feeding Buffers into the Plan 208

But This Is So Much Work 210

Summary 210

Discussion Questions 211

Part V: Tracking and Communicating 213 Chapter 19: Monitoring the Release Plan 215

Tracking the Release 216

Release Burndown Charts 219

A Parking-Lot Chart 224

Summary 225

Discussion Questions 226

Chapter 20: Monitoring the Iteration Plan 227

The Task Board 227

Iteration Burndown Charts 230

Tracking Effort Expended 231

Individual Velocity 232

Summary 232

Discussion Questions 233

Chapter 21: Communicating about Plans 235

Communicating the Plan 237

Communicating Progress 238

An End-of-Iteration Summary 241

Summary 244

Discussion Questions 245

Part VI: Why Agile Planning Works 247 Chapter 22: Why Agile Planning Works 249

Replanning Occurs Frequently 249

Estimates of Size and Duration Are Separated 250

Plans Are Made at Different Levels 251

Plans Are Based on Features, Not Tasks 252

Small Stories Keep Work Flowing 252

Work in Process Is Eliminated Every Iteration 252

Tracking Is at the Team Level 253

Uncertainty Is Acknowledged and Planned For 253

A Dozen Guidelines for Agile Estimating and Planning 254

Summary 256

Discussion Questions 257

Part VII: A Case Study 259 Chapter 23: A Case Study: Bomb Shelter Studios 261

Day 1—Monday Morning 262

Estimating the User Stories 270

Preparing for Product Research 281

Iteration and Release Planning, Round 1 284

Two Weeks Later 302

Planning the Second Iteration 303

Two Weeks Later 305

Revising the Release Plan 305

Presenting the Revised Plan to Phil 308

Eighteen Weeks Later 312

Reference List 313 Index 319

Preface

This book could have been called Estimating and Planning Agile Projects. Instead, it's called Agile Estimating and Planning. The difference may appear subtle, but it's not. The title makes it clear that the estimating and planning processes must themselves be agile. Without agile estimating and planning, we cannot have agile projects.

The book is mostly about planning, which I view as answering the question of 'What should we build and by when?' However, to answer questions about planning we must also address questions of estimating ('How big is this?') and scheduling ('When will this be done?' and 'How much can I have by then?').

This book is organized in seven parts and twenty-three chapters. Each chapter ends with a summary of key points and with a set of discussion questions. Because estimating and planning are meant to be whole-team activities, one of the ways I hope this book will be read is by teams who meet perhaps weekly to discuss what they've read and the questions at the end of each chapter. Because agile software development is popular worldwide, I have tried to avoid writing an overly United States-centric book. To that end, I have used the universal currency symbol, writing amounts such as ¤500 instead of perhaps $500 or €500 and so on.

Part I describes why planning is important, the problems we often encounter, and the goals of an agile approach. Chapter 1 begins the book by describing the purpose of planning, what makes a good plan, and what makes planning agile. The most important reasons why traditional approaches to estimating and planning lead to unsatisfactory results are described in Chapter 2. Finally, Chapter 3 begins with a brief recap of what agility means and then describes the high-level approach to agile estimating and planning taken by the rest of this book.

The second part introduces a main tenet of estimating, that estimates of size and duration should be kept separate. Chapters 4 and 5 introduce story points and ideal days, two units appropriate for estimating the size of the features to be developed. Chapter 6 describes techniques for estimating in story points and ideal days, and includes a description of planning poker. Chapter 7 describes when and how to re-estimate, and Chapter 8 offers advice on choosing between story points and ideal days.

Part III, 'Planning for Value,' offers advice on how a project team can make sure they are building the best possible product. Chapter 9 describes the mix of factors that need to be considered when prioritizing features. Chapter 10 presents an approach for modeling the financial return from a feature or feature set and how to compare financial returns so that the team works on the most valuable items first. Chapter 11 includes advice on how to assess and then prioritize the desirability of features to a product's users. Chapter 12 concludes this part with advice on how to split large features into smaller, more manageable ones.

In Part IV, we shift our attention and focus on questions around scheduling a project. Chapter 13 begins by looking at the steps involved in scheduling a relatively simple, single-team project. Next, Chapter 14 looks at how to plan an iteration. Chapters 15 and 16 look at how to select an appropriate iteration length for the project and how to estimate a team's initial rate of progress. Chapter 17 looks in detail at how to schedule a project with either a high amount of uncertainty or a greater implication to being wrong about the schedule. This part concludes with Chapter 18, which describes the additional steps necessary in estimating and planning a project being worked on by multiple teams.

Once a plan has been established, it must be communicated to the rest of the organization and the team's progress against it monitored. These are the topics of the three chapters of Part V. Chapter 19 looks specifically at monitoring the release plan, while Chapter 20 looks at monitoring the iteration plan. The final chapter in this part, Chapter 21, deals specifically with communicating about the plan and progress toward it.

Chapter 22 is the lone chapter in Part VI. This chapter argues the case for why agile estimating and planning work and stands as a counterpart to Chapter 2, which describes why traditional approaches fail so often.

Part VII, the final part, includes only one chapter. Chapter 23 is an extended case study that reasserts the main points of this book but does so in a fictional setting.