agile patterns: estimation - stephen forte | falafelcon 2014
DESCRIPTION
We’re agile, so we don’t have to estimate and have no deadlines, right? Wrong! This session will consist of review of the problem with estimation in projects today and then an overview of the concept of agile estimation and the notion of re-estimation. We’ll learn about user stories, story points, team velocity, how to apply them all to estimation and iterative re-estimation. We will take a look at the cone of uncertainty and how to use it to your advantage. We’ll then take a look at the tools we will use for Agile Estimation, including planning poker. We will then take an alternative approach and look at using real metrics to limit the guesswork in estimating and still run a team that produces predictably and reliably. This is a very interactive session, so bring a lot of questions!TRANSCRIPT
Making Agile Es-ma-on Work
Stephen Forte @worksonmypc
I’m Steve
Es-ma-on Defined (sort of)
• Problem is that es.mates become a unbreakable schedule, where any devia.on is considered bad
“Es$ma$on is the calculated approxima$on of a result which is usable even if input data may be incomplete or uncertain.”
— Wikipedia
The Es-ma-on Problem • When you come up with a project idea, your first es.mate is off by +/4x • Not enough details are known
• Tradi.onally too much .me is spent on building a specifica.on which is not complete • Again, not enough details are known
• As .me progresses, more details emerge about the system and its details • The cone of uncertainty
The Cone of Uncertainty 4x
2x
1.5x
1.25x
1.0x
.8x
.67x
.5x
25x
Agile Es-ma-on • Es.ma.on is uncertain by defini.on! • Problem is that es.mates become an unbreakable schedule, where any devia.on is considered bad
• Agile Es.ma.on throws this logic away and always re-‐es.mates a project aIer each itera.on • Different value system, devia.ons are not devia.ons, they are more accurate es.ma.ons • Uses the cone of uncertainty to your advantage
How to Es-mate
User Stories
Story Points
Planning Poker
Product Backlog
Velocity
Re-‐es-ma-on
Beyond Es-ma-on: Metrics
Reading List
Books we have read and recommend: • User Stories Applied by Mike Cohn • Agile Es0ma0ng and Planning by Mike Cohn • Agile Retrospec0ves by Esther Derby and Diana Larsen
Ques-ons?