To Estimate or Not to Estimate,

Is that the Question?

#leanagileUS @mattphilipLeanAgileUS Conference, 27 Feb 2017

Hofstadter’s Law

“It always takes longer than you

expect, even when you take into

account Hofstadter’s Law.”

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Parkinson’s Law

“Work expands so as to fill the

time available for its completion."

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”Poor Estimation Skills”

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The Spectrum of Estimating

Never EstimateAnything

Always Estimate

Everything

Question purpose of estimatingInclude all sources of variation

Focus on characterizing workProbabilistic forecast

Use delivery dataLess effort spent

Estimation cultureConsider effort onlyDeterministic forecastUse intuitionHeavy effort involvedTasks in hours

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What NoEstimates is not saying

• You are evil if you estimate

• All estimates are totally useless

• Stop doing your successful estimating practice

• Stop having the conversations to understand/analyze/break down work

• Work items must be the same size

• You must place your full faith and confidence in Monte Carlo forecasts

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What NoEstimates is saying

• Know why you are estimating

• Discover for yourself how good you are at estimating (measure)

• Keep doing the things that help you understand the work

• Upfront estimates need to be held loosely

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NoEstimates, Manifesto Style

… We have come to value:

Probabilistic over Deterministic

Delivery time over Development time

MVP scope over Full scope

Data over Intuition*

Reducing sources of variation over Improving estimating

That is, while there is value in the items on the right, we value the items on the left more.

*Neil Kil l ick uses “empiricism over guesswork”

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Sources of Variation

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Do You Assume Correlation?

Is the initial sizing a good predictor for when you can get your stuff? In our case, the surprising truth was ”no.”

-- Mattias Skarin, Real-World Kanban

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What’s Going On?Low process efficiency (typically 5-15% in

software delivery) means that even if we

nailed the effort estimates … we would be

accurately predicting 5-15% of elapsed

delivery time!

-- Troy Magennis

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Other Sources of Variation

Often system factors account for more of the elapsed delivery time than different

story sizes.

-- Troy Magennis

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Sources of Variation

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How many can you name?

Sources of Variation

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• WIP

• Technology/domain/product

• Team composition

• User, client and client representative

• Multitasking/focus factor

• Market and competitors

• System dependencies

• Team dependencies

• Specialization

• Waiting for availability

• Rework

• Steps/handoffs (50%*50%*50%...)

• Stages in team development (Tuckman)

• Selection policy

• Essential complication (How hard a problem

is on its own)

• Accidental complication (“How much we

suck at our jobs” -Rainsberger)

First, Know Where You Are

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Keogh’s “Scale of Ignorance”

1. Just about everyone in the world has done this.

2. Lots of people have done this, including someone on our team.

3. Someone in our company has done this, or we have access to expertise.

4. Someone in the world did this, but not in our organization (and probably at a

competitor).

5. Nobody in the world has ever done this before.

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What Can You Do About Variation?

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How many remediescan you name?

What You Can Do About Variation

• Lower WIP

• ConWIP/System WIP

• Five Focusing Steps

• Blocker clustering

• Reduce workflow stages

• Explicit policies

• Cost of Delay scheduling, sequencing and selection

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Lean

-Kan

ban

What You Can Do About Variation

• “Agile 101” (simple, decoupled design; thin vertical slices; pairing)

• Identify/make visible/measure dependencies

• Collaborate/Share work (Dimitar Bakardzhiev)

• Spike and stabilize (Dan North)

• Reduce accidental complexity (Liz Keogh)

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Team

Why?

“Business” Considerations

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NoEstimates and the Business

• Determine what actions would be different based on the estimate

• Customer-based fitness criteria

• Budgeting: Team run rate

• Focus conversation on value, not cost

• MVP and product ownership

• Create probabilistic forecast ASAP (as soon as you have data) – together!

• Service-Delivery Reviews

• Teams: Keep teams together, dedicated (reduces context-switching, Tuckman stages)

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To Estimate or Not to Estimate?

Never EstimateAnything

Always Estimate

Everything

Question purpose of estimatingInclude all sources of variation

Focus on characterizing workProbabilistic forecast

Use delivery dataLess effort spent

Estimation cultureConsider effort onlyDeterministic forecastUse intuitionHeavy effort involvedTasks in hours

#leanagileUS @mattphilip

A better question:What can you do to maximize value and

reduce risk in planning and delivery?

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• noestimatesbook.com (Vasco Duarte)

• focusedobjective.com (Troy Magennis)

• actionableagile.com (Dan Vacanti)

• infoq.com/articles/noestimates-monte-carlo

(Dimitar Bakardzhiev)

• priceonomics.com/why-are-projects-always-

behind-schedule/

• scrumandkanban.co.uk/estimation-meets-

cynefin/

• ronjeffries.com

• lizkeogh.com

• neilkillick.com

• zuill.us

• mattphilip.wordpress.com/tag/noestimates

References and More Info

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