Estimation and Trust

Intentionally Vague Slide Noel Rappin, Estimates and Trust, Ancient City
Ruby 2015. http://www.noelrappin.com http://www.tablexi.com @noelrap

How far do you live from an airport? Noel Rappin,
Estimates and Trust, Ancient City Ruby 2015. http://www.noelrappin.com http://www.tablexi.com @noelrap

I live !" minutes from one Noel Rappin, Estimates and
Trust, Ancient City Ruby 2015. http://www.noelrappin.com http://www.tablexi.com @noelrap

If I'm in a car And the weather is good
And it's not rush hour And I don't blow a tire Noel Rappin, Estimates and Trust, Ancient City Ruby 2015. http://www.noelrappin.com http://www.tablexi.com @noelrap

Failing any of these makes my trip longer Noel Rappin,

Estimation and Trust Noel Rappin, Table XI Noel Rappin, Estimates
and Trust, Ancient City Ruby 2015. http://www.noelrappin.com http://www.tablexi.com @noelrap

Noel Rappin, Estimates and Trust, Ancient City Ruby 2015. http://www.noelrappin.com
http://www.tablexi.com @noelrap

I am an idiosyncratic crank about estimates Noel Rappin, Estimates

Are software developers uniquely bad at estimates? Noel Rappin, Estimates

Ever done a home remodel? Noel Rappin, Estimates and Trust,
Ancient City Ruby 2015. http://www.noelrappin.com http://www.tablexi.com @noelrap

Big Dig Noel Rappin, Estimates and Trust, Ancient City Ruby
2015. http://www.noelrappin.com http://www.tablexi.com @noelrap

Initial cost estimate $5.8 billion !!!!!! Noel Rappin, Estimates and

Final cost: $21.93 billion And counting... !!!!!!!!!!! !!!!!!!!!!! Noel Rappin,

It's not just our problem Noel Rappin, Estimates and Trust,

Why do we need to estimate? Noel Rappin, Estimates and

What about #noestimates? Noel Rappin, Estimates and Trust, Ancient City

I'll stop estimating when my clients stop asking Noel Rappin,

Communication Noel Rappin, Estimates and Trust, Ancient City Ruby 2015.
http://www.noelrappin.com http://www.tablexi.com @noelrap

Estimating Projects: Communicates client investment Noel Rappin, Estimates and Trust,

Estimating Projects: Allows us to gauge progress Noel Rappin, Estimates

Estimating Projects: Enables us to think about the problem Noel
Rappin, Estimates and Trust, Ancient City Ruby 2015. http://www.noelrappin.com http://www.tablexi.com @noelrap

Estimating Projects Badly: Sets unrealistic expectations Noel Rappin, Estimates and

Estimating Projects Badly: Encourages micromanaging Noel Rappin, Estimates and Trust,

Estimating Projects Badly: Stops us from thinking about the problem
Noel Rappin, Estimates and Trust, Ancient City Ruby 2015. http://www.noelrappin.com http://www.tablexi.com @noelrap

Estimating at the beginning is the worst Noel Rappin, Estimates

Like guessing time to the airport if you don't even
know where the airport is Or if you even need to fly... Noel Rappin, Estimates and Trust, Ancient City Ruby 2015. http://www.noelrappin.com http://www.tablexi.com @noelrap

How can we estimate Effectively? Ethically? Noel Rappin, Estimates and

Estimating projects vs. Estimating features Noel Rappin, Estimates and Trust,

Nobody really cares about estimating features Noel Rappin, Estimates and

They only care about when users can use stuff Noel
Rappin, Estimates and Trust, Ancient City Ruby 2015. http://www.noelrappin.com http://www.tablexi.com @noelrap

Feature estimates are only useful to get you to project
estimates Noel Rappin, Estimates and Trust, Ancient City Ruby 2015. http://www.noelrappin.com http://www.tablexi.com @noelrap

A quick sidebar of agile terms Noel Rappin, Estimates and

Feature Story Iteration Point Velocity Noel Rappin, Estimates and Trust,

Kind of a theory of ethical estimates Noel Rappin, Estimates

Estimates are estimates Noel Rappin, Estimates and Trust, Ancient City

Estimates are probabilistic Noel Rappin, Estimates and Trust, Ancient City

Chance of rain: 50% ☔ Noel Rappin, Estimates and Trust,

We can make bad assumptions Noel Rappin, Estimates and Trust,

Misunderstanding the problem Noel Rappin, Estimates and Trust, Ancient City

Scope Creep Noel Rappin, Estimates and Trust, Ancient City Ruby

Unknown complexity Noel Rappin, Estimates and Trust, Ancient City Ruby

Rework Noel Rappin, Estimates and Trust, Ancient City Ruby 2015.

Political issues Optimism Pressure Noel Rappin, Estimates and Trust, Ancient
City Ruby 2015. http://www.noelrappin.com http://www.tablexi.com @noelrap

Can we do better? Noel Rappin, Estimates and Trust, Ancient

Focus on what we're good at Noel Rappin, Estimates and

Avoid false precision Noel Rappin, Estimates and Trust, Ancient City

What goes into the amount of calendar time a feature
takes? Noel Rappin, Estimates and Trust, Ancient City Ruby 2015. http://www.noelrappin.com http://www.tablexi.com @noelrap

Complexity of the task Skill of the developer Time on
task Noel Rappin, Estimates and Trust, Ancient City Ruby 2015. http://www.noelrappin.com http://www.tablexi.com @noelrap

We are bad at estimating time on task Noel Rappin,

But it tends to be consistent over time Noel Rappin,

Skill of the developer Noel Rappin, Estimates and Trust, Ancient

We're also not that great at estimating this Noel Rappin,

And it's toxic Noel Rappin, Estimates and Trust, Ancient City

But it tends to be consistent over time Noel Rappin,

We are pretty good at estimating complexity Noel Rappin, Estimates

Which is to say ! ⚪ ! Noel Rappin, Estimates

Estimate complexity and let time sort itself out Noel Rappin,

Which is like basing our airport estimate on: Distance to
airport Average speed in the past Noel Rappin, Estimates and Trust, Ancient City Ruby 2015. http://www.noelrappin.com http://www.tablexi.com @noelrap

Consistency Noel Rappin, Estimates and Trust, Ancient City Ruby 2015.

Of team size Of story makeup Of environment Noel Rappin,

Decomposing the problem into similar size chunks helps Noel Rappin,

Requires Time Noel Rappin, Estimates and Trust, Ancient City Ruby

How do I estimate at the beginning of a project?

The worst way to estimate (except for all the other
ways) Noel Rappin, Estimates and Trust, Ancient City Ruby 2015. http://www.noelrappin.com http://www.tablexi.com @noelrap

Fake it Noel Rappin, Estimates and Trust, Ancient City Ruby

Don't fake knowledge or precision Noel Rappin, Estimates and Trust,

Realize that your output is a range Noel Rappin, Estimates

Split the tasks as best you can Noel Rappin, Estimates

Assign points 1: easy, less than a day 3: has
complexity or risk 5: has a lot more complexity or risk Noel Rappin, Estimates and Trust, Ancient City Ruby 2015. http://www.noelrappin.com http://www.tablexi.com @noelrap

Don't spend a lot of time assigning points to a
single task Noel Rappin, Estimates and Trust, Ancient City Ruby 2015. http://www.noelrappin.com http://www.tablexi.com @noelrap

Round up Noel Rappin, Estimates and Trust, Ancient City Ruby

At the beginning (and only at the begining) You can
range estimate stories Noel Rappin, Estimates and Trust, Ancient City Ruby 2015. http://www.noelrappin.com http://www.tablexi.com @noelrap

Range of points Noel Rappin, Estimates and Trust, Ancient City

load factor (5 - 7 hours per point) Noel Rappin,

Low point total * low factor High point total *
high factor Noel Rappin, Estimates and Trust, Ancient City Ruby 2015. http://www.noelrappin.com http://www.tablexi.com @noelrap

points * factor = hours hours * rate = estimate

Present this with humility Noel Rappin, Estimates and Trust, Ancient

Understand that this will change Noel Rappin, Estimates and Trust,

You are headed to the airport together Noel Rappin, Estimates

Thanks Image credits 4 http://www.constructionequipmentguide.com/ historical/big-dig/ Noel Rappin, Estimates and

Noel Rappin Table XI @noelrap http://www.noelrappin.com/trdd http://pragprog.com/book/nrtest2 Noel Rappin, Estimates

Estimation and Trust

Estimation and Trust

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