The document discusses user story point estimation, proposing a new structured method to improve the reliability and consistency of effort estimation in software development. It highlights key problems with current estimation methods, such as subjectivity and environmental factors, and outlines the factors considered in the new approach. The document also provides a mathematical formula for calculating use case points and emphasizes the advantages of the new estimation method.

1. USER STORY
POINT
ESTIMATION
South Wales Agile Group

2. Hello!
I am Fred Heath
Developer, Problem solver, Ruby
evangelist, Agile practitioner.
You can find me at:
@FredAtBootstrap
bootstrap.me.uk

5. SCRUM
ESTIMATION
○ Planning Poker
○ T-Shirt Size
○ Fruit Eating
○ ….and others
Story
Points

8. “There is currently no standard unit
of measurement in software
development

9. “Current estimation measures effort
without accounting for factors that
affect said effort

10. What’s this all about
○ Current estimation methods not fit for
purpose
○ A new structured, empirical way
introduced: USP estimation
USP = User Story Point

12. 4 -
easy

13. 4 -
easyNot to
me - 16

14. but, look
here……
…………..
easy, see?

15. I suppose
you’re
right,
4 then!

19. 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.

20. Key problems with current
estimation methods
○ Inconsistent
○ Subjective
○ Unreliable

21. 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

22. USER STORY POINT ESTIMATION
A consistent, reliable, structured, empirical
estimation method

23. Use Case Point
Estimation
for Object-Oriented, Use-Case
based development

24. 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

25. UCP References
1. 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

26. UCP
USP
Object-Orientated
UML
Waterfall
Multi-paradigm
Agile
Use Cases
User Stories

27. USP - STEP 1
PRODUCTIVITY
FACTORS

28. Productivity Factors
0.5
1.5
1
1
1
-1
-1
1.5
0 1 2-1-2

29. 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

30. P FACTOR
PF = 1.4 + (-0.03*Total Impact)

31. USP - STEP 2
USER STORY
COMPLEXITY

32. COMPLEXITY FACTORS
Weight Name
2
Distributed or Parallel
processing
2 Concurrency
2 High Performance
1 Reusability & Modularity
1
Complex internal
Processing

33. COMPLEXITY FACTORS (cont’d)
Weight Name
0.5 Ease of Use
1.5 Cross-Platform Support
0.5
Complex Setup or
installation
1
Extensibility &
Compliance
1 Security

34. USER STORY COMPLEXITY
Complexity Score (USCS) =
5 + Σ{Weights}

35. USER STORY POINTS
USP = USCS * PF

36. Example:
Shopping app
Estimate during planning meeting.
Whole team participates.

37. PRODUCTIVITY FACTORS
Name Weight Score Impact
Project Familiarity 1.5 4 6
Application Experience 0.5 4 2
Proramming paradigm
experience
1 2 2
Team Cohesion 1 4 4

38. PRODUCTIVITY FACTORS
Name Weight Score Impact
User Story Robustness 1.5 5 7.5
New / part-time team-
members
-1 3 -3
Proramming language
complexity
-1 3 -3
Motivation 1 5 5
TOTAL IMPACT = 20.5

39. P FACTOR
PF = 1.4 + (-0.03*20.5)
= 0.785

40. 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 = 7

41. USER STORY POINTS
USP = 7 * 0.785
= 5.495
=~ 5.5

42. USP ADVANTAGES
○ Objective
○ Repeatable
○ Quick to apply
○ Adaptable to change

43. “The greatest gift is the power to
estimate things at their true worth.
Francois de la Rochefoucauld

44. Discussion, suggestions, feedback
https://muut.com/usp-estimation

45. 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

46. THANKS!
Any questions?
You can find me at:
@FredAtBootstrap
fred@bootstrap.me.uk