How Big Is It? A guide to agile estimation and planning

E0ac0a6053ca7d1a65eba75ff6f6791b?s=47 Mike Pearce
October 18, 2012

How Big Is It? A guide to agile estimation and planning

Estimating the size of stories, features or work is pretty confusing. What with fibonacci, a modified fibonacci, t-shirt sizes, animals and other various and often arbitrary methods of sizing things, it's no wonder that developers struggle to do it and the business often has little, or no confidence in the estimates from your team.

This talk will delve into the ideas behind estimating methods, weighing up the pros and cons and discusses how to estimate work items, how to use these estimates to create a velocity or derive cycle-time and how to get better at sizing almost anything you like with accuracy, as well as helping the business understand your estimates and what they mean (and don't mean!) and whether, in fact, estimating is even necessary! All this in order to achieve estimation nirvana.

E0ac0a6053ca7d1a65eba75ff6f6791b?s=128

Mike Pearce

October 18, 2012
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Transcript

  1. Mike Pearce How big is it?

  2. Mike Pearce How big is it?

  3. #bestTalkEver

  4. Introduction

  5. @mikepearce /mikepearce.net mike@mikepearce.net /in/mikeypearce

  6. None
  7. What is estimating? The art of estimating Planning What it

    really means
  8. Unluckily all these positive assertions are contrary to that very

    experience, which is pleaded for them, nor have we any idea of self, after the manner it is here explain’d. For from what impression cou’d this idea be deriv’d? This question ’tis impossible to answer without a manifest contradiction and absurdity; and yet ’tis a question, which must necessarily be answer’d, if we wou’d have the idea of self pass for clear and intelligible. It must be some one impression, that gives rise to every real idea. But self or person is not any one impression, but that to which our several impressions and ideas are suppos’d to have a reference. If any impression gives rise to the idea of self, that impression must continue invariably the same, thro’ the whole course of our lives; since self is suppos’d to exist after that manner. But there is no impression constant and invariable. Pain and pleasure, grief and joy, passions and sensations succeed each other, and never all exist at the same time. It cannot, therefore, be from any of these impressions, or from any other, that the idea of self is deriv’d; and consequently there is no such idea. But there is no impression constant and invariable. Pain and pleasure, grief and joy, passions and sensations succeed each other, and never all exist at the same time. It cannot, therefore, be from any of these impressions, or from any other, that the idea of self is deriv’d; and consequently there is no such idea.
  9. What is estimating? Estimation problems Planning What is estimating?

  10. "Estimation is the process of finding an estimate, or approximation,

    which is a value that is usable for some purpose even if input data may be incomplete, uncertain, or unstable." Wikipedia "Estimation is the process of finding an estimate, or approximation, which is a value that is usable for some purpose even if input data may be incomplete, uncertain, or unstable." "Estimation is the process of finding an estimate, or approximation, which is a value that is usable for some purpose even if input data may be incomplete, uncertain, or unstable." by ~jjjohn~ - http://flic.kr/p/4CYJT1
  11. Guessing?

  12. Wikipedia [A Guestimate] is defined as an estimate made without

    using adequate or complete information, or, more strongly, as an estimate arrived at by guesswork or conjecture. [A Guestimate] is defined as an estimate made without using adequate or complete information, or, more strongly, as an estimate arrived at by guesswork or conjecture. [A Guestimate] is defined as an estimate made without using adequate or complete information, or, more strongly, as an estimate arrived at by guesswork or conjecture. by ~jjjohn~ - http://flic.kr/p/4CYJT1
  13. What is estimating? Estimation problems Planning What it really means

    The art of estimating
  14. The lone ranger

  15. None
  16. Delphi Method

  17. Wideband Delphi

  18. Unluckily all these positive assertions are contrary to that very

    experience, which is pleaded for them, nor have we any idea of self, after the manner it is here explain’d. For from what impression cou’d this idea be deriv’d? This question ’tis impossible to answer without a manifest contradiction and absurdity; and yet ’tis a question, which must necessarily be answer’d, if we wou’d have the idea of self pass for clear and intelligible. It must be some one impression, that gives rise to every real idea. But self or person is not any one impression, but that to which our several impressions and ideas are suppos’d to have a reference. If any impression gives rise to the idea of self, that impression must continue invariably the same, thro’ the whole course of our lives; since self is suppos’d to exist after that manner. But there is no impression constant and invariable. Pain and pleasure, grief and joy, passions and sensations succeed each other, and never all exist at the same time. It cannot, therefore, be from any of these impressions, or from any other, that the idea of self is deriv’d; and consequently there is no such idea. But there is no impression constant and invariable. Pain and pleasure, grief and joy, passions and sensations succeed each other, and never all exist at the same time. It cannot, therefore, be from any of these impressions, or from any other, that the idea of self is deriv’d; and consequently there is no such idea. Unluckily all these positive assertions are contrary to that very experience, which is pleaded for them, nor have we any idea of self, after the manner it is here explain’d. For from what impression cou’d this idea be deriv’d? This question ’tis impossible to answer without a manifest contradiction and absurdity; and yet ’tis a question, which must necessarily be answer’d, if we wou’d have the idea of self pass for clear and intelligible. It must be some one impression, that gives rise to every real idea. But self or person is not any one impression, but that to which our several impressions and ideas are suppos’d to have a reference. If any impression gives rise to the idea of self, that impression must continue invariably the same, thro’ the whole course of our lives; since self is suppos’d to exist after that manner. But there is no impression constant and invariable. Pain and pleasure, grief and joy, passions and sensations succeed each other, and never all exist at the same time. It cannot, therefore, be from any of these impressions, or from any other, that the idea of self is deriv’d; and consequently there is no such idea. But there is no impression constant and invariable. Pain and pleasure, grief and joy, passions and sensations succeed each other, and never all exist at the same time. It cannot, therefore, be from any of these impressions, or from any other, that the idea of self is deriv’d; and consequently there is no such idea. 263
  19. Is there a best way to estimate?

  20. “Ideal Time”

  21. By slworking2 - http://flic.kr/p/cvY16A

  22. We suck at Temporal Estimation

  23. Vierordt’s Law (1968): Retrospectively, "short" intervals of time tend to

    be overestimated, and "long" intervals of time tend to be underestimated. Vierordt’s Law (1868): Retrospectively, "short" intervals of time tend to be overestimated, and "long" intervals of time tend to be underestimated. 1818 - 1884
  24. (Buehler & Griffin, 2003; Buehler, Griffin, & MacDonald, 1997; Buehler,

    Griffin, & Ross, 1994; Bueh­ ler, Messervey, & Griffin, 2005; Byram, 1997; Connolly & Dean, 1997; Francis­ Smythe & Robertson, 1999; Grif­ fin & Buehler, 1999; Jorgensen & Sjoberg, 2001; Josephs & Hahn, 1995; Koneçni & Ebbesen, 1976; König, 2005; Koole & Van’t Spijker, 2000; Kruger & Evans, 2004; Molokken­Ostvold & Jorgensen, 2005; Newby­Clark, Ross, Buehler, Koehler, & Griffin, 2000; Taylor, Pham, Rivkin, & Armor, 1998)
  25. Sounds bad, what’s the solution?

  26. RAE’s

  27. Time? Effort? Anything? NO

  28. Relative, arbitrary estimates

  29. Fibonacci

  30. None
  31. Fibonacci 1, 1, 2, 3, 5, 8, 13, 21, 34,

    55 ...
  32. Modified Fibonacci 0, 1, 2, 3, 5, 8, 13, 20,

    40, 100, ?
  33. Story Points 0, 1, 2, 3, 5, 8, 13, 20,

    40, 100, ?
  34. 0 1 2 3 5 8 13 20 40 100

    =3 (or, as big as a 1 and 2) Bigger than a 1, a 2 AND a 3 Too big
  35. Let’s build a thing with Audience Participation!

  36. 3 8 13 8 2 1 3 8 5 8

    1 5 Gut feel for sprint 1 Priority order
  37. Pop Quiz Hotshot!

  38. Cone of uncertainty

  39. 4x 1x 0.25x 1.25x 1.5x 2x 0.8x 0.67x 0.5x Time

    Estimate variability Cone of uncertainty
  40. Begin sprint 1

  41. Velocity = 13

  42. 5 8 13 8 2 1 3 8 5 8

    1 5 Sprint 1 successful Priority order Sprint 2 Sprint 3 Sprint 4 Sprint 5 Sprint 6 Velocity: 13
  43. Begin sprint 2

  44. Velocity = 15

  45. 5 8 13 8 2 1 3 8 5 8

    1 5 Sprint 1 successful Priority order Sprint 2 successful Sprint 3 Sprint 4 Sprint 5 Velocity: 13 Velocity: 15
  46. 4x 1x 0.25x 1.25x 1.5x 2x 0.8x 0.67x 0.5x Time

    Estimate variability Cone of uncertainty Sprint 2
  47. And that’s all there is to arbitrary, relative estimates... Simple,

    right?
  48. Also...

  49. Tshirt sizes XS, S, M, L, XL

  50. Cycle Time How long does it take for one story

    to get from here to here. To do In Progress Testing Done In 12 days, we will be here s m m s s
  51. Similar sized stories

  52. In the real world

  53. Planning poker

  54. None
  55. None
  56. None
  57. Tips Do not do overtime No anchoring Make assumptions explicit

    Build in slack
  58. What if we don’t know?

  59. Spike

  60. We got it wrong ;(

  61. None
  62. None
  63. The law of large numbers

  64. You’re using them for what?!

  65. Estimate != Quote By Dan’s Photos = http://flic.kr/p/NPEcM

  66. Wikipedia "Estimation is the process of finding an estimate, or

    approximation, which is a value that is usable for some purpose even if input data may be incomplete, uncertain, or unstable." by ~jjjohn~ - http://flic.kr/p/4CYJT1
  67. By Stéfan - http://flic.kr/p/7oYXjh

  68. Re-estimating

  69. 4x 1x 0.25x 1.25x 1.5x 2x 0.8x 0.67x 0.5x Time

    Estimate variability Cone of uncertainty Sprint x
  70. Oh crap, we forgot...

  71. Documentation (5%) Dependencies Env/platform setup Non-spike research Overheads

  72. What is estimating? Estimation problems Planning What it really means

    Planning
  73. Vision Road Map Release Planning

  74. sarahG - http://flic.kr/p/5iykd4 Name your project

  75. leadfoot36 - http://flic.kr/p/532uc7 Review velocity and iteration schedule

  76. jayneandd - http://flic.kr/p/7MhBfD Review your definition of done

  77. LAC/BAC - http://flic.kr/p/88qSVk Review your stories

  78. ognjen.odobasic- http://flic.kr/p/7Dy6qc Itinerant Tightwad - http://flic.kr/p/6Cun3D Scope or date release?

  79. LaserGuided - http://flic.kr/p/639Ke Review architecture and technology

  80. p_a_h - http://flic.kr/p/8nzn6R Allocate stories to sprints

  81. Discuss problems, issues and assumptions

  82. Why do this?

  83. TGV - http://flic.kr/p/2Q1sC1

  84. publicenergyhttp://flic.kr/p/dxeYi

  85. dimodi - http://flic.kr/p/8wNsoS

  86. None
  87. None
  88. None
  89. Anticipation Adaptation frankenstoen - http://flic.kr/p/6o7wc2

  90. Vision Road Map Release Planning Sprint Planning

  91. I need ... So that ... As a ... I

    need ... So that ... 2 As a ... I need ... So that ... 8 As a ... 3
  92. None
  93. None
  94. None
  95. Vision Road Map Release Planning Sprint Planning Standup

  96. How do I start a project?

  97. With this guy By huangjiahui - http://flic.kr/p/5pE12U White Elephant Sizing

  98. 1 2 3 8 13 20 ? 5 As a

    ... I need ... So that ... As a ... I need ... So that ... As a ... I need ... So that ... As a ... I need ... So that ... As a ... I need ... So that ... As a ... I need ... So that ... As a ... I need ... So that ... As a ... I need ... So that ... As a ... I need ... So that ... 5 1 3 2 5 13 3 2 8 Total story points: 300
  99. As a ... I need ... So that ... 3

    As a ... I need ... So that ... 2 As a ... I need ... So that ... 8 ENOUGH! Estimated Velocity: 13
  100. CAVEAT LECTOR

  101. I need ... So that ... As a ... I

    need ... So that ... 2 As a ... I need ... So that ... 8 1 4 9 3 1 6 2 7 4 6 6 Total Hours For Sprint 1: 144 As a ... 3 7 4 4 2
  102. Hours Range Tim Bob Bex Max Min Range 6 7

    60-70 3 5 30-50 4 5 40-50 Hours per sprint 130-170
  103. MATHS FUN Total story points / Estimated Velocity = Estimated

    No. Sprints 300 / 13 = 23
  104. 1 2 3 8 13 20 ? 5 As a

    ... I need ... So that ... As a ... I need ... So that ... As a ... I need ... So that ... As a ... I need ... So that ... As a ... I need ... So that ... As a ... I need ... So that ... As a ... I need ... So that ... As a ... I need ... So that ... As a ... I need ... So that ... 5 1 3 2 5 13 3 2 8 Total story points: 300
  105. As a ... I need ... So that ... 3

    As a ... I need ... So that ... 2 As a ... I need ... So that ... 8 ENOUGH! Estimated Velocity: 13
  106. MATHS FUN Estimated No. Sprints x Estimated hours for sprint

    1 = Total Hours For Project 23 x 144 = 3312 Total story points / Estimated Velocity = Estimated No. Sprints 300 / 13 = 23
  107. I need ... So that ... As a ... I

    need ... So that ... 2 As a ... I need ... So that ... 8 1 4 9 3 1 6 2 7 4 6 6 As a ... 3 7 4 4 2 Total Hours For Sprint 1: 144
  108. MATHS FUN Estimated No. Sprints x Estimated hours for sprint

    1 = Total Hours For Project 23 x 144 = 3312 Total Hours For Project / Min Sprint Hours = Minimum Number of Sprints 3312 / 130 = 25 sprints Total story points / Estimated Velocity = Estimated No. Sprints 300 / 13 = 23
  109. Hours Range Tim Bob Bex Max Min Range 6 7

    60-70 3 5 30-50 4 5 40-50 Hours per sprint 130-170
  110. MATHS FUN Estimated No. Sprints x Estimated hours for sprint

    1 = Total Hours For Project 23 x 144 = 3312 Total Hours For Project / Min Sprint Hours = Minimum Number of Sprints 3312 / 130 = 25 sprints Total Hours For Project / Max Sprint Hours = Maximum Number of Sprints 3312 / 170 = 19 sprints Total story points / Estimated Velocity = Estimated No. Sprints 300 / 13 = 23
  111. Hours Range Tim Bob Bex Max Min Range 6 7

    60-70 3 5 30-50 4 5 40-50 Hours per sprint 130-170
  112. 19-25 sprints

  113. Already got a velocity?

  114. Start of 8 sprint project Average Best Worst Almost definitely

    Probably Maybe Not a chance
  115. Estimation problems Planning The answer... What it really means

  116. “I have always found that plans are useless, but planning

    is indispensable.” General Dwight. D. Eisenhower
  117. None
  118. Estimation is hard and can sometimes be impossible, but it

    is a learnable skill and when you can do it and do it well, it can be a great aid to agility and efficiency. - Paul Dyson, 2010
  119. None
  120. Kano Model Delighted! Dissatisfied Need not fulfilled Need fulfilled

  121. I N V E S T ndpendent egotiable aluable stimable

    mall estable
  122. M o S C o W ust have hould have

    ould have ont have
  123. Burndowns

  124. 0 10 20 30 40 50 1 2 3 4

    5 6 7 8 9 10 Tasks/Hours Days Sprint Burndown
  125. 0 25 50 75 100 1 2 3 4 5

    6 7 8 9 10 Tasks/Hours Days Sprint Burndown
  126. 0 25 50 75 100 1 2 3 4 5

    6 7 8 9 10 Tasks/Hours Days Sprint Burndown
  127. 0 25 50 75 100 1 2 3 4 5

    6 7 8 9 10 Tasks/Hours Days Sprint Burndown
  128. 0 25 50 75 100 1 2 3 4 5

    6 7 8 9 10 Story Points Days Sprint Burndown
  129. 0 25 50 75 100 1 2 3 4 5

    6 7 8 9 10 Story Points Days Sprint Burndown
  130. 0 175 350 525 700 01/01/2011 30/01/2011 24/02/2011 17/03/2011 18/04/2011

    Story Points Days Release Burndown