Practical Story SizingBrett MaytomSenior Consultant, Readify

Vic .NET – 13 Aug 2011

Talk Backlog What is size Relative Size Sizing Scales Velocity Story Size versus Task Sizing Running Sizing Meetings Questions

What is size? Unit of measure for work

Why Relative Sizing Your Time IS NOT My Time

Size does not … indicate time Indicate skill include risk change over time Increase\decrease with proficiency

Relative

EqualHalfDouble

Four Times

Three Times

It’s relative

Sizing Scales Fibonacci

1 2 3 5 8 13 21 34 Modified Fibonacci

1 2 3 5 8 13 20 50 100 Binary

1 2 4 8 16 32 64 128 T-Shirt

S M L XL

Other Symbols 0 (Zero)

“Too small and not worth sizing” ?

“I have no idea what you are talking about” ∞ (Infinity)

“This is way too big”

Velocity Rate of work of team

“Team can complete X story points per sprint” Not individual Full team

including BA, QA, Dev., Test, Architect, Scrum Master

Improves with time

Story Sizing Uses a relative sizing scale Not done at iteration planning Used for Release Planning

Stories and Tasks

Task Sizing Tasks defined in sprint planning Sized in hours Updated daily with remaining hours Used for sprint burndown Cross-check against Story Size using

current velocity

Sizing in multi-team Consistent story size critical Large scope differences Clear benchmarks Central team

How to play Planning Poker Product owner presents a story

Team clarify by asking questions “1 … 2 … 3 … show” Smallest and largest values explain Repeat until consensus reached

Spikes Totally new technology Never done before Have no idea how to size work

Time-boxed to a few days

Acid TestA story sized in the first sprint should have the same size in later sprints

Practical Tips Use relative sizes for stories Do not factor in effort, risk and time Build a list of benchmark stories Continually inspect that “time” is not

introduced story Differentiate between Task and Story

sizes Your Time IS NOT My Time

Thank you

Brett Maytombrett.maytom@readify.net@brettmaytomhttp://brett.maytom.net