Fix you some bad estimation habits

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fix you estimating bad habits TED M. YOUNG RENAISSANCE CODER & AGILE/LEAN HERETIC AT GUIDEWIRE SOFTWARE

description

Slides as given for the Feb. 12, 2014 talk at Bay Area Software Testers. (btw, I failed to give credit for the "Stand Back!" t-shirt image, it was from the XKCD T-shirt here: http://store-xkcd-com.myshopify.com/products/try-science) Also forgot reference to the paper on Fibonacci numbers in planning poker affecting estimates: http://simula.no/publications/Simula.simula.1282/simula_pdf_file

Transcript of Fix you some bad estimation habits

Page 1: Fix you some bad estimation habits

fix youestimatingbad habitsTED M. YOUNG

RENAISSANCE CODER & AGILE/LEAN HERETIC

AT GUIDEWIRE SOFTWARE

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estimating bugsAND OTHER "OVERHEAD"

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ignoring all previousor other projectsREFERENCE CLASS FORECASTING (OUTSIDE VIEW)

LARGE ORGS HAVE AN ADVANTAGE HERE

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The prevalent tendency to underweight, or ignore, distributional information is perhaps the major error of intuitive prediction.

TVERSKY & KAHNEMAN, 1977

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ignoring variabilityof velocityVELOCITY CAN EXHIBIT A ± 2× SPREAD OF VARIATION

Bad habit number 8

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not using statistics

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STATISTICS

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From: Troy Magennis 2012

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using single valuesNEGLECTING DISTRIBUTIONAL INFORMATION

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WHAT WE THINK OUR ESTIMATE DISTRIBUTION IS

Image from "Estimates in Software Development", Dubakov 2013

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flaw of averagesWHY EVERYTHING IS BEHIND SCHEDULE

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ESTIMATE DISTRIBUTION IS MORE LIKE LOG-NORMAL OR WEIBULL

ATTRIBUTE SUBSTITUTION?Image from "Estimates in Software Development", Dubakov 2013

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treating every type of estimate the same wayEPICS, THEMES, STORIES, TASKS: POINTS FOR ALL!

Bad habit number 3

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ignoring value ofthing being estimatedSPEND LOTS OF TIME ON THINGS OF LITTLE VALUE

CUZ IT'S EASIER!

Bad habit number

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think about your estimate not theirsYOU UNDERESTIMATE YOUR OWN COMPLETION TIME

BUT NOT OTHERS'!

Bad habit number

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estimatingthings you'llnever work on

Bad habit number 5

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only estimatingtouch timeDISCUSSION? COORDINATION? BAH, WHO NEEDS IT?

Bad habit number 3

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estimating timeinstead ofcomplexity or effortPOINTS/SIZES GET EQUATED TO TIME

IN BOTH DIRECTIONS!

Bad habit number 9

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completion dateorhours of work?THEY'RE NOT THE SAME THING

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using non-linearvalues for estimatingFIBONACCI AND NON-LINEAR SEQUENCES DECREASE ESTIMATES

USE T-SHIRT SIZES INSTEAD

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using planning pokerATTEMPT TO REMOVE ANCHORING BIAS

REPLACES IT WITH SOCIAL ANXIETY

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estimating what we think the story isINSTEAD OF WHAT IT ACTUALLY IS

WHAT WILL BE DIFFERENT IF THIS STORY IS IMPLEMENTED?

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premature estimationHAVE YOU EXPLORED THE OPTIONS BEFORE COMMITTING?

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treating all estimatesas commitmentsNOT APPROPRIATE

UNTIL WE GET BETTER AT ESTIMATING

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practicing estimationwithout deliberatenessPRACTICE ≠ DELIBERATE PRACTICE

REF. DEFINITION OF INSANITY

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not experimentingIF ESTIMATING DOESN'T DO EVERYTHING YOU NEED

HOW ARE YOU TRYING TO IMPROVE?

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overvaluingestimationSTOP FIGHTING OVER PRECISION

YOUR ACCURACY DOESN'T MATTER EITHER

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deliberate deceptionTHE MACHIAVELLI FACTOR OR OVERLY SUBSERVIENT

BOWING TO POLITICAL PRESSURE

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assuming youneed estimatesMAYBE YOU DON'T?

HOW WOULD YOU FIND OUT?

#NOESTIMATES

Bad habit number 1

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Final Questions?TWITTER - @JITTERTED EMAIL - [email protected]

HTTP://ABOUT.ME/TEDMYOUNG

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Resources 50 Quick Ideas to Improve Your User Stories (In-progress Leanpub e-book)

◦ http://leanpub.com/50quickideas

Throughput (Blog entry by Zsolt Fabók)◦ http://zsoltfabok.com/blog/2014/01/throughput/

Intuitive Prediction (1977 paper by Kahneman & Tversky about the "planning fallacy")◦ http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA047747

Judgment under uncertainty (1974 paper by Tversky & Kahneman)◦ http://www.sciencemag.org/content/185/4157/1124.short

Delusions of Success: How Optimism Undermines Executives' Decisions (Lovallo & Kahneman)◦ http://j.mp/delusions-of-success

Modeling, Simulation & data mining (Slides from Troy Magennis & Larry Maccherone)◦ http://j.mp/simulation-magennis

Estimates in Software Development (Dubakov, May 2013)◦ http://www.targetprocess.com/articles/estimates-software-development.html