Essential Scrum
Essential Scrum

Chapter 7: Estimation and Velocity

This chapter describes the concepts of estimation and velocity. I begin with an overview of the important roles that estimation and velocity play in agile planning. I then discuss the various items that we estimate and when and how we estimate them. The bulk of the chapter focuses on how to estimate product backlog items, including how to choose a unit of measure and use Planning Poker. Next I move on to the concept of velocity and how using a velocity range is essential for planning. I discuss how new teams can forecast velocity in the absence of historical data. I conclude with ways we can influence velocity and how velocity can be misused.

Chapter Contents:

  • Overview
  • What and When We Estimate
    • Portfolio Backlog Item Estimates
    • Product Backlog Estimates
    • Task Estimates
  • PBI Estimation Concepts
    • Estimate as a Team
    • Estimates Are Not Commitments
    • Accuracy versus Precision
    • Relative Size Estimation
  • PBI Estimation Units
    • Story Points
    • Ideal Days
  • Planning Poker
    • Estimation Scale
    • How to Play
    • Benefits
  • What Is Velocity?
  • Calculate a Velocity Range
  • Forecasting Velocity
  • Affecting Velocity
  • Misusing Velocity
  • Closing