Embed Size (px)
Citation preview
BW10Session6/8/164:15PM
ProjectEstimation:Myths,Taboos,andInconvenientTruths
Presentedby:
RobertMerrill
UniversityofWisconsin-Madison
Broughttoyouby:
350CorporateWay,Suite400,OrangePark,FL32073888---268---8770··[email protected]://www.techwell.com/
RobertMerrillUniversityofWisconsin-MadisonAsahurricanescientistinthe1980s,RobertMerrillknewestimationwasaboutforecastingandresponse.(Controlnevercrossedhismind.)Asascientificapplicationsprogrammerinthe1990s,Roberthonedhisestimationskillsinself-defenseagainstprojectmanagement.In2003,askedtocreateafailure-proofapplicationcontractinganddeliveryprocess,Robertfinallyfacedtherealityoftheestimationproblemandgraspedthebusinessessenceofprojectsuccess.Histarget-budget,variable-scopeapproachhelpedturnaroundhisprojectstoprofitability,referenceability,andsustainability.Hethenspentsevenyearsasanindependentconsultant,refiningtheprinciplesandmakingthemclearandconvincing.RobertpresentlyservestheUniversityofWisconsin-Madisonasaprojectintakespecialistandbusinessanalyst.
6/19/2016
1
Warm-upIntroduce yourself to your neighbor.Answer, “How do you produce, consume, or experience project or release-level estimates?”Describe your feelings about the topic of estimation.
Robert T. MerrillSenior Business AnalystDivision of Information Technology (DoIT)University of Wisconsin–Madison
Project EstimationMyths, Taboos, and Inconvenient Truths
6/19/2016
2
The Estimation Problem1. Estimates are ranges2. Ranges are larger than we think3. Ranges cost more to reduce than we feel they should, or can afford4. Ranges are too big to live with
What I want you to hear1. Estimation Problem drives many others2. Thinking is impaired
– Myths (blindness)– Taboos (shame)– Inconvenient Truths (avoidance)
3. A respectful solution
6/19/2016
3
We’re Bad Estimators
BaseballWhat’s “Good?”
6/19/2016
4
McConnell’s Cone
Reading the Cone1000 h
4x1000=4000 h0.25x1000=250 h
“Initial Concept” estimateExpect 16x range
6/19/2016
5
Behind the ConeScatter2x
½x
Cone Caveats1. Not your shop, not your data2. YMMV, and probably worse3. Doesn’t converge if you’re dysfunctional
6/19/2016
6
For every complex problemthere is an answer that isclear, simple, and wrong.—H. L. Mencken
Clear, Simple, & Wrong
The solution is properdefinition and planning
6/19/2016
7
Cone Ranges and Costs“Up Front”doesn’t equal “Instant and Free”
4x 2x
% of Project Cost Estimate Range, low to highBuffer, % of 50/50 estimate
2-4% ~4x 100%4-6% ~3x 70%
8-12% ~2x 40%20-25% ~1.5x 20%
Cost of Accurate Estimates
6/19/2016
8
Sources of Uncertainty
The Estimation ProblemWe can’t afford estimatesthat are accurate enoughto make estimation errorsa non-significant risk.Inconvenient Truth
6/19/2016
9
That’s what eveningsand weekends are for
Crunch ModeStanford
Stanford Univ. Dept. of Computer Science
“Thus, while employers do notallow their employees to come towork drunk, they oftenperpetuate working conditionslike crunch mode that yield thesame net effect.”
6/19/2016
10
Doom Loop: Behind
PRESSURE!PRESSURE!
Doom Loop: PressureDoom Loop: Pressure
6/19/2016
11
PRESSURE!PRESSURE!
Doom Loop: PressureDoom Loop: Mistakes
PRESSURE!PRESSURE!MoreTo Do!
MoreTo Do!MoreTo Do!MoreTo Do!
Doom Loop: PressureDoom Loop: More Work!
6/19/2016
12
Aggressive plansstill yieldthe best possible results
Gyroscope
6/19/2016
13
Cost
Quality
The software most of us are making
AvionicsNuke ControlsRadiotherapy
Cost-Quality curve
DoomLoopZone
Schedule
Cost ParkinsonZone
Cost-Schedule Curve
6/19/2016
14
I don’t think it means…
Crunch modeis really about provingwe tried really hard
6/19/2016
15
I just need a rough estimate.I won’t hold you to it.—Pinocchio
Management has a legitimate need for estimatesInconvenient Truth
6/19/2016
16
Requested datesaren’t estimates
Estimateshave probabilitiesand/or ranges
6/19/2016
17
Estimates aren’t commitments
What they ask forRange and probabilitiesaround a requestWhat you agreeto try to make happen
Vocabulary• Request / Demand
• Estimate
• Commitment
6/19/2016
18
Is it an estimate?• Project effort estimate is 3500 h• Project effort has a 50% chance of being 3500 hours or less• Project duration is estimatedat 6-8 months• The 50%-90% chance project duration is 6-8 months
YesOK, but…
Yes
Avoiding Games & Drama• Vocabulary• Awareness (“Thomsett estimation games”)
https://www.cutter.com/article/double-dummy-spit-and-other-estimating-games-405811• Hard Soft Skills Dialogue Boundaries Negotiation
6/19/2016
19
Padding is unprofessional
Commitments?
Estimates?
Trains always on time. Is this happening?
Isn’t thismore common?
Parkinson’s Law?
6/19/2016
20
Can we live with it?
2x~50%
What if wepadded the scope?
6/19/2016
21
In the beginning…In the beginning was the ship date, and the specification was without form, and void…--Inception 1:1
Scope: A Big Pile of Rocks
6/19/2016
22
Which do you understand?
Where uncertainty really isProject uncertaintyreally wants to bein the scope.
Inconvenient Truth
6/19/2016
23
Cutting scopemeans we’ve failed
Project Success RedefinedProject Successis delivering results that areworth more than they costwithout running out oftime and money.
6/19/2016
24
We do this.We always scope projects to fit.That’s what you heard,not what I mean
I can’t estimate
6/19/2016
25
No, you can’t, can you?
The hardest thingis giving upthe illusion of controlat the beginning.—”Uncle Bob” Martin
6/19/2016
26
This sounds like a cop-out!• BAs, stakeholder analysis is good• So is data and function modeling• PMs, planning is goodBut the estimation problem remains!Diminishing returns, folks!
Variable scope? How?• A dice game• Burn-up charts
6/19/2016
27
Estimation Risk GameWork in pairs or threes~15 minutesFollow the instructions first, then experimentThen we’ll discuss
The Scope-Schedule Swap
6/19/2016
28
The Scope-Schedule Swap+ +++ ?
The Scope-Schedule Swap
+
6/19/2016
29
The Scope-Schedule Swap
The Scope-Schedule Swap
6/19/2016
30
The Scope-Schedule Swap
The Scope-Schedule Swap
+
6/19/2016
31
1. Crazy big ranges2. Don’t squeeze the goose3. Up-front work can’t save you4. Pad the scope5. Do Phase Two right away6. Included for free with agile
