The Project Manager's Guide to Mastering Agile, 2nd Edition

7Agile Estimation

AGILE ESTIMATION OVERVIEW

THIS CHAPTER IS DESIGNED TO PROVIDE A HIGH-LEVEL OVERVIEW OF AGILE ESTIMATION PRACTICES and how they are different from classical plan‐driven estimation practices. References to other Agile estimation techniques that are outside the scope of this book will be provided at the end of this chapter.

What’s Different about Agile Estimation?

Before discussing Agile estimation, it’s important to have an understanding of what’s different about the environment for an Agile project, because there are some very significant differences that affect how you would do any kind of estimation.

A classical plan‐driven or Waterfall project is usually based on somewhat of a contractual relationship between the business users and the project team.

• Typically, the business users agree to some fairly well‐defined requirements and sign off on them prior to the start of the project.
• The project team then commits to a cost and delivery schedule to meet those requirements and any changes in the scope of the requirements are controlled from that point forward.
• In order to manage the reliability of the estimates, some kind of disciplined process for managing changes to the requirements is implemented, and significant changes are considered to be an exception rather than the norm.
• If a significant change takes place, it normally triggers an assessment to determine the impact on the costs and schedule of the project and any initial estimates are recalculated and ...