USER STORY POINT ESTIMATION

Hello!I am Fred Heath

Developer, Problem solver, Ruby evangelist, Agile practitioner.

You can find me at:@FredAtBootstrapbootstrap.me.uk

“There is currently no standard unit

of measurement in software development

What’s this all about

○ Current estimation methods not fit for purpose

○ A new structured, empirical way introduced: USP estimation

USP = User Story Point

4 - easy

4 - easyNot to

me - 16

but, look here………………..easy, see?

I suppose you’re right,4 then!

What went wrong

Environmental factors ignored

Ben unfamiliar with project, programming language and application domain.

Technical factors ignored

Asynchronous processing is inherently complex, setup is not trivial.

Human interaction factors ignored

Jerry charismatic and influential leader. Peer pressure always wins.

Key problems with story points

○ Inconsistent

○ Subjective

○ Unreliable

Velocity Assumptions

○ Stable previous velocity○ Team doesn’t change○ Sprint duration doesn’t change○ Initial planning session is inerrant○ Technology / platform doesn’t change○ Individual productivity doesn’t change

USER STORY POINT ESTIMATION

A consistent, reliable, structured, empirical estimation method

Use Case Point Estimation

for Object-Oriented, Use-Case based development

Use Case Points

Environmental Factors (EF)

Project familiarity, application experience, motivation, language complexity, etc.

Technical Factors (TF)

Complex algorithms, concurrency, cross-platform support, etc.

Use Case complexity (UUCP)

Simple, average or complex

Use Case Points = UUCP * TCF * ECF

UCP References1. Karner, G, 1993, “Metrics for Objectory”. Diploma thesis, University

of Linköping, Sweden. No. LiTHIDA-Ex-9344:21. December 1993.2. Smith, John, 1999, “The Estimation of Effort Based on Use-Cases.

Rational Software.Cupertino, CA.TP-171. October 1999.3. Anda, Bente, D. Dreiem, Dag Sjøberg and Magne Jørgensen, 2001,

“Estimating Software Development Effort Based on Use-Cases - Experiences from Industry”, The Unified Modeling Language.Modeling Languages, Concepts, and Tools, 4th International Conference, Toronto, Canada, October 1-5, 2001, LNCS 2185

4. Roy Clem, Project Estimation with Use Case Points, http://www.codeproject.com/KB/architecture/usecasep.aspx

USP - STEP 1PRODUCTIVITY FACTORS

Productivity Factors

0.5

1.5

1

1

1

-1

-1

1.5

0 1 2-1-2

Total Impact

= F1 weight * F1 score+ F2 weight * F2 score + F3 weight * F3 score + F4 weight * F4 score + F5 weight * F5 score + F6 weight * F6 score + F7 weight * F7 score + F8 weight * F8 score

X

P FACTOR

PF = 1.4 + (-0.03*Total Impact)

USP - STEP 2USER STORY COMPLEXITY

COMPLEXITY FACTORS

Factor Name

A1 Distributed or Parallel processing

A2 Concurrency

A3 High Performance

B1 Reusability & Modularity

B2 Complex internal Processing

COMPLEXITY FACTORS (cont’d)

Factor Name

B3 Ease of Use

B4 Cross-Platform Support

B5 Complex Setup or installation

B6 Extensibility & Compliance

B7 Security

USER STORY COMPLEXITY

Complexity Condition USCP

Simple No complexity factors apply 5

Average 1-2 B factors, but no A factor apply

10

Complex At least one A factor, or more than 2 B factors, apply

15

USER STORY POINTS

USP = USCP * PF

PRODUCTIVITY FACTORS

Name Weight Score Impact

Project Familiarity 1.5 4 6

Application Experience 0.5 4 2

Proramming paradigm experience

1 5 5

Team Cohesion 1 4 4

PRODUCTIVITY FACTORS

Name Weight Score Impact

User Story Robustness 1.5 5 7.5

New team-members -1 3 -3

Proramming language complexity

-1 3 -3

Motivation 1 5 5

TOTAL IMPACT = 23.5

P FACTOR

PF = 1.4 + (-0.03*23.5)= 0.695

User Story

Epic: “As a user, I want to backup my hard drive.”

Story: “As a power user, I can specify files or

folders to backup based on file size, date created and date modified.”

USCP = 10

USER STORY POINTS

USP = 10 * 0.695= 6.95

USP ADVANTAGES

○ Objective

○ Repeatable

○ Quick to apply

○ Adaptable to change

“The greatest gift is the power to

estimate things at their true worth.

Francois de la Rochefoucauld

CREDITS

Special thanks to all the people who made and released these awesome resources for free:○ Simple line icons by Mirko Monti○ E-commerce icons by Virgil Pana○ Streamline iconset by Webalys○ Presentation template by SlidesCarnival

THANKS!Any questions?

You can find me at:@FredAtBootstrapfred@bootstrap.me.uk