Mike Pearce (MOO.COM) How big is it? A guide to agile estimation practices Agile on the Beach...
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Transcript of Mike Pearce (MOO.COM) How big is it? A guide to agile estimation practices Agile on the Beach...
Mike PearceHow big is it?
#bestTalkEver
Introduction
What is estimating?
Estimation problems
Planning
What does it all mean?
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.
What is estimating?
Estimation problems
Planning
What does it all mean?
What is estimating?
Wikipedia
by ~jjjohn~ - http://flic.kr/p/4CYJT1
"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."
"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."
Guessing?
Wikipedia
by ~jjjohn~ - http://flic.kr/p/4CYJT1
[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.
Yes, guessing
What is estimating
Estimation problems
Planning
What does it all mean
The problem with estimates
Problem #1 The lone ranger
What about ‘Group Think’?
Illusion of invulnerability.
Collective rationalisation.
Belief in inherent morality.
Stereotyped views of out-groups. Direct pressure on dissenters
Self-censorship Illusion of unanimity
Self-appointed ‘mindguards’
Symptoms
Delphi Method
Wideband Delphi
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
Problem #2 Estimation is hard
“Ideal Time”
We suck at Temporal Estimation
Vierordt’s Law (1968): !Retrospectively, "short" intervals of time tend to be overestimated, and "long" intervals of time tend to be underestimated. 1818 - 1884
Vierordt’s Law (1968): !Retrospectively, "short" intervals of time tend to be overestimated, and "long" intervals of time tend to be underestimated.
(Buehler & Griffin, 2003; Buehler, Griffin, & MacDonald, 1997; Buehler, Griffin, & Ross, 1994; Bueh ler, Messervey, & Griffin, 2005; Byram, 1997; Connolly & Dean, 1997; FrancisSmythe & 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)
Sounds bad, what’s the solution?
Relative, arbitrary estimates
Time?
Effort?
Anything?NO
Relative, arbitrary estimates
Fibonacci
Fibonacci
0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55 ...
Modified Fibonacci
0, 1, 2, 3, 5, 8, 13, 20, 40, 100, ?
Story Points
0, 1, 2, 3, 5, 8, 13, 20, 40, 100, ?
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
Let’s build a thing with Audience
Participation!
And that’s all there is to arbitrary, relative
estimates... !
Simple, right?
What else is there?
Tshirt sizes
XS, S, M, L, XL
Tshirt sizes
Goat designed by Joseph Gray from The Noun Project
Cycle TimeHow long does it take for one story
to get from here to here.
To do In Progress Testing Done
In 8 days, we will be here
Tips
Do not do overtime
No anchoring
Make assumptions explicit
Build in slack
Problem #3 Being clueless
Spike
Problem #4 Getting it wrong
The law of large numbers
Problem #5 Misuse of estimates
Estimate != Quote
By Dan’s Photos = http://flic.kr/p/NPEcM
Wikipedia
by ~jjjohn~ - http://flic.kr/p/4CYJT1
"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."
Problem #6 Not estimating
overheads
Documentation (5%)
Dependencies
Env/platform setup
Non-spike research
Overheads
Problem #7 Misleading the
estimators
So, which method is best?
What is estimating
Estimation problems
Planning
What does it all mean
Planning
Vision
Road Map
Release Planning
Vision
Road Map
Release Planning
Sprint Planning
3813821385
8
15
Gut feel for sprint 1Priority order
Pop Quiz Hotshot!
Cone of uncertainty
4x
1x
0.25x
1.25x
1.5x
2x
0.8x
0.67x
0.5x
Time
Estim
ate variability
Cone of uncertainty
3813821385
8
15
Gut feel for sprint 1Priority order
Begin sprint 1
Velocity
= 13
5813
82
1385
8
15
Sprint 1 successfulPriority order
Sprint 2
Sprint 3
Sprint 4
Sprint 5
Sprint 6
Velocity: 13
Begin sprint 2
Velocity
= 15
5813
82
1385
8
15
Sprint 1 successfulPriority order
Sprint 2 successful
Sprint 3
Sprint 4
Sprint 5
Velocity: 13
Velocity: 14
4x
1x
0.25x
1.25x
1.5x
2x
0.8x
0.67x
0.5x
Time
Estim
ate variability
Cone of uncertainty
Sprin
t 2
Start of 8 sprint project
Average 15pts
Best 20pts
Worst 10pts
Almost definitely
Probably
Maybe
Not a chance
Total No. of Points: 300
Re-estimating
4x
1x
0.25x
1.25x
1.5x
2x
0.8x
0.67x
0.5x
Time
Estim
ate variability
Cone of uncertainty
Sprin
t x
Vision
Road Map
Release Planning
Sprint Planning
Standup
What is estimating
Estimation problems
Planning
The answer...What does it all mean?
About this big…
Dan NorthEmbracing Uncertainty
“Some unexpected bad things will happen.”
#noEstimates
Empirical data will help
improve accuracy
Develop and refine your own estimation
models
“I have always found that plans are useless, but planning is indispensable.”
General Dwight. D. Eisenhower
How do I start a
project?
With this guy
By huangjiahui - http://flic.kr/p/5pE12U
White Elephant Sizing
1 2 3 5
8 13 20 ?
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
CAVEAT LECTOR
As a ... I need ... So that ...
3
As a ... I need ... So that ...
2
As a ... I need ... So that ...
8
1 4 2 3
1 4 9 3
1 6 2 7
46
6
Total Hours For Sprint 1: 144
As a ... I need ... So that ...
3
6
74
4
4 2
Hours Range
TimBobBex
Max
MinRange
6 7 60-703 5 30-504 5 40-50
Hours per sprint 130-170
MATHS FUN
Estimated No. Sprints x Estimated hours for sprint 1
= Total Hours For Project23 x 144 = 3312Total Hours For Project / Min Sprint Hours
= Minimum Number of Sprints3312 / 130 = 25 sprintsTotal Hours For Project / Max Sprint Hours
= Maximum Number of Sprints3312 / 170 = 19 sprints
Total story points / Estimated Velocity = Estimated No. Sprints
300 / 13 = 23
19-25 sprints
Kano ModelDelighted!
Dissatisfied
Need not
fulfilled
Need fulfilled
INVEST
ndpendentegotiablealuablestimablemallestable
M o S Co W
ust have
hould haveould haveont have
