I Estimate This Talk is 30 Minutes (Give or take 10)

This slide Intentionally left blank Noel Rappin, This talk is
20 30 minutes long, RubyConf 2015. http://www.noelrappin.com | http://www.tablexi.com | @noelrap

How far do you live from an airport? Noel Rappin,
This talk is 20 30 minutes long, RubyConf 2015. http://www.noelrappin.com | http://www.tablexi.com | @noelrap

I live !" minutes from one Noel Rappin, This talk
is 20 30 minutes long, RubyConf 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, This talk is 20 30 minutes long, RubyConf 2015. http://www.noelrappin.com | http://www.tablexi.com | @noelrap

Failing any of these makes my trip longer Noel Rappin,

This talk is 20 30 minutes (give or take 10)
Noel Rappin, Table XI (@noelrap) Noel Rappin, This talk is 20 30 minutes long, RubyConf 2015. http://www.noelrappin.com | http://www.tablexi.com | @noelrap

Noel Rappin, This talk is 20 30 minutes long, RubyConf
2015. http://www.noelrappin.com | http://www.tablexi.com | @noelrap

I am an idiosyncratic crank about estimates Noel Rappin, This
talk is 20 30 minutes long, RubyConf 2015. http://www.noelrappin.com | http://www.tablexi.com | @noelrap

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

Ever done a home remodel? Noel Rappin, This talk is

Big Dig Noel Rappin, This talk is 20 30 minutes
long, RubyConf 2015. http://www.noelrappin.com | http://www.tablexi.com | @noelrap

Initial cost estimate $5.8 billion !!!!!! Noel Rappin, This talk

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

It's not just our problem Noel Rappin, This talk is

What can we do about it? Noel Rappin, This talk

What if we didn't estimate? Noel Rappin, This talk is

What if we just did stuff and got paid? Noel
Rappin, This talk is 20 30 minutes long, RubyConf 2015. http://www.noelrappin.com | http://www.tablexi.com | @noelrap

Sure, I'll tear up your kitchen. And bill you when
I'm done. Noel Rappin, This talk is 20 30 minutes long, RubyConf 2015. http://www.noelrappin.com | http://www.tablexi.com | @noelrap

Customers reasonably expect estimates Noel Rappin, This talk is 20
30 minutes long, RubyConf 2015. http://www.noelrappin.com | http://www.tablexi.com | @noelrap

Estimates are Communication Noel Rappin, This talk is 20 30
minutes long, RubyConf 2015. http://www.noelrappin.com | http://www.tablexi.com | @noelrap

Communication with $$$ Noel Rappin, This talk is 20 30

Estimates communicate: investment Noel Rappin, This talk is 20 30

Estimates communicate: progress Noel Rappin, This talk is 20 30

Estimates communicate: scope Noel Rappin, This talk is 20 30

Bad Estimates communicate: Unrealistic expectations Noel Rappin, This talk is

Bad Estimates communicate: Way too much... Noel Rappin, This talk

So, let's just do good Estimates Noel Rappin, This talk

Estimating at the beginning is the worst Noel Rappin, This

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, This talk is 20 30 minutes long, RubyConf 2015. http://www.noelrappin.com | http://www.tablexi.com | @noelrap

How can we estimate Effectively? Noel Rappin, This talk is

Even when we know Nothing Noel Rappin, This talk is

A quick sidebar of agile terms Noel Rappin, This talk

Feature / Story The unit of work in a project
Noel Rappin, This talk is 20 30 minutes long, RubyConf 2015. http://www.noelrappin.com | http://www.tablexi.com | @noelrap

Iteration The unit of planning in a project Noel Rappin,

Point The size of a story Noel Rappin, This talk

Velocity Points per interation Noel Rappin, This talk is 20

Kind of a theory of estimates Noel Rappin, This talk

Estimating projects vs. Estimating features Noel Rappin, This talk is

Nobody really cares about estimating features Noel Rappin, This talk

They only care about when users can use stuff Noel

Feature estimates are only useful to get you to project
estimates Noel Rappin, This talk is 20 30 minutes long, RubyConf 2015. http://www.noelrappin.com | http://www.tablexi.com | @noelrap

Estimates are estimates Noel Rappin, This talk is 20 30

Estimates are probabilistic Noel Rappin, This talk is 20 30

Chance of rain: 50% ☔ Noel Rappin, This talk is

This is a ! point story Noel Rappin, This talk

What makes an estimate wrong? Noel Rappin, This talk is

Bad assumptions Noel Rappin, This talk is 20 30 minutes

Misunderstanding the problem Noel Rappin, This talk is 20 30

Scope Creep Noel Rappin, This talk is 20 30 minutes

Unknown complexity Noel Rappin, This talk is 20 30 minutes

Rework Noel Rappin, This talk is 20 30 minutes long,
RubyConf 2015. http://www.noelrappin.com | http://www.tablexi.com | @noelrap

Developers are optimists Noel Rappin, This talk is 20 30

Sometimes there is pressure Noel Rappin, This talk is 20

A lower estimate doesn't make it less complex Noel Rappin,

How to do better Noel Rappin, This talk is 20

Uncertanty Not Precision Noel Rappin, This talk is 20 30

What goes into the amount of calendar time a feature
takes? Noel Rappin, This talk is 20 30 minutes long, RubyConf 2015. http://www.noelrappin.com | http://www.tablexi.com | @noelrap

Complexity of the task Skill of the developer Time on
task Noel Rappin, This talk is 20 30 minutes long, RubyConf 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, This talk is 20

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

And it's toxic Noel Rappin, This talk is 20 30

But it tends to be consistent over time Noel Rappin,

We are pretty good at estimating complexity Noel Rappin, This

Which is to say ! ⚪ ! Noel Rappin, This

Estimate complexity and let time sort itself out Noel Rappin,

The humble point Noel Rappin, This talk is 20 30

Time on task and relative skill average out Noel Rappin,

Which is like basing our airport estimate on: Distance to
airport Average speed in the past Noel Rappin, This talk is 20 30 minutes long, RubyConf 2015. http://www.noelrappin.com | http://www.tablexi.com | @noelrap

Consistency Noel Rappin, This talk is 20 30 minutes long,
RubyConf 2015. http://www.noelrappin.com | http://www.tablexi.com | @noelrap

Of team size Of story makeup Of environment Noel Rappin,

Decomposing the problem into similar size chunks helps Noel Rappin,

But you need data Noel Rappin, This talk is 20

The problem of one-off estimates Noel Rappin, This talk is

How do I estimate at the beginning of a project?

The worst way to estimate (except for all the other
ways) Noel Rappin, This talk is 20 30 minutes long, RubyConf 2015. http://www.noelrappin.com | http://www.tablexi.com | @noelrap

Fake it Noel Rappin, This talk is 20 30 minutes

Don't fake knowledge Noel Rappin, This talk is 20 30

Fake your velocity Noel Rappin, This talk is 20 30

Don't spend time chasing precision Noel Rappin, This talk is

your output is a range Noel Rappin, This talk is

Split the tasks as best you can Noel Rappin, This

Assign points 1: easy, less than a day 3: has
complexity or risk 5: has a lot more complexity or risk Noel Rappin, This talk is 20 30 minutes long, RubyConf 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, This talk is 20 30 minutes long, RubyConf 2015. http://www.noelrappin.com | http://www.tablexi.com | @noelrap

Round up Noel Rappin, This talk is 20 30 minutes

At the beginning (and only at the begining) You can
range estimate stories Noel Rappin, This talk is 20 30 minutes long, RubyConf 2015. http://www.noelrappin.com | http://www.tablexi.com | @noelrap

You end up with Range of points Say... (100 -
120) Noel Rappin, This talk is 20 30 minutes long, RubyConf 2015. http://www.noelrappin.com | http://www.tablexi.com | @noelrap

Apply a load factor (5 - 7 hours per point)

Low points * low factor High points * high factor
= (100 * 5) - (120 * 7) = (500 - 840) hours Noel Rappin, This talk is 20 30 minutes long, RubyConf 2015. http://www.noelrappin.com | http://www.tablexi.com | @noelrap

hours * rate = estimate = ($75,000 - $126,000) Noel

Clearly describe the limits Noel Rappin, This talk is 20

Understand that this will change Noel Rappin, This talk is

You are headed to the airport together Noel Rappin, This

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

Noel Rappin (@noelrap) Table XI http://www.noelrappin.com/trdd (coupon code RUBYCONF2015) http://pragprog.com/book/nrtest2

I Estimate This Talk is 30 Minutes (Give or take 10)

I Estimate This Talk is 30 Minutes (Give or take 10)

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