1.
@gil_zilberfeld
Planning
with #NoEstimates

2.
@gil_zilberfeld
Hello!
I AM GIL ZILBERFELD
www.gilzilberfeld.com
www.everydayunittesting.com
@gil_zilberfeld

3.
@gil_zilberfeld
That is the
question

4.
@gil_zilberfeld
The founders

5.
@gil_zilberfeld
Why do we
need
estimates?

6.
@gil_zilberfeld
Ask the
expert

7.
@gil_zilberfeld
Why do we
want
estimates?

8.
@gil_zilberfeld
Better decisions
Go / No / Not now
Alternatives
Be in control

9.
@gil_zilberfeld
Why don’t we
like giving
estimates?

10.
@gil_zilberfeld
Treated as
commitments
Inflated
Waste of time

11.
@gil_zilberfeld
The main
problem is…

12.
@gil_zilberfeld
Do they help
make better
decisions?

13.
@gil_zilberfeld
We’re not
good at
estimating

14.
@gil_zilberfeld
“Prediction is very
difficult, especially
about the future.” Niels Bohr,
Nobel Prize in Physics

15.
@gil_zilberfeld
The cone of
uncertainty

16.
@gil_zilberfeld
“It always takes longer
than you expect,
even when you take into
account
Hofstadter's Law”
Douglas Hofstadter
Professor of cognitive
science

17.
@gil_zilberfeld
The estimation game
For each of the next 10 quantitative questions,
give a lower and an upper bound,
such that you believe with about 90%
certainty that the
correct answer lies within the interval given.

18.
@gil_zilberfeld
The estimation game
This means that you should expect to guess
correctly for about 9 questions out of 10.

19.
@gil_zilberfeld
Q: How many people are in this room?
A: You ‘guess’ an interval: 2-100

20.
@gil_zilberfeld
Ready?

21.
@gil_zilberfeld
1. What was the date of birth of Bram Stoker,
author of Dracula?

22.
@gil_zilberfeld
2. What is the population of the Republic of
Brazil?

23.
@gil_zilberfeld
3. What is the height, in meters, of the tallest
living redwood tree?

24.
@gil_zilberfeld
4. How many standardized (ISO 6346) steel
shipping containers exist in the world?

25.
@gil_zilberfeld
5. How many Boeing 747 (all models) have been
built at this date?

26.
@gil_zilberfeld
6. What is the total number of human deaths
attributed to H5N1 “avian” flu?

27.
@gil_zilberfeld
7. How many Syrian conflict refugees were
registered by UNHCR as of 1 Nov 2012?

28.
@gil_zilberfeld
8. What was the total wine production of France
in 2009, in hectoliters?

29.
@gil_zilberfeld
9. How many Olympics medals altogether have
been won to date by Austrian athletes?

30.
@gil_zilberfeld
10. What is the half-life, in years, of the isotope
Plutonium 239?

31.
@gil_zilberfeld
1) 1847
2) 199 million
3) 115 meters
4) 20 million containers
5) 1486 747s
You can also split your content
6) 379 deaths
7) 286,000 refugees
8) 45 million hectoliters
9) 304 medals
10) 24 thousand years
How did you do?

32.
@gil_zilberfeld
So what happened?

33.
@gil_zilberfeld
I’ll tell you

34.
@gil_zilberfeld
This is what I
want

35.
@gil_zilberfeld
“The primary purpose of an
estimate is not to predict a
project’s outcome.
Steve McConnell, Software Estimation (2006)
It is to determine whether a
project’s targets are realistic
enough to allow the project
to be controlled to meet
them.”

36.
@gil_zilberfeld
Let’s assume
and estimate
costs!

37.
@gil_zilberfeld
Estimates are
not the only
tools

38.
@gil_zilberfeld
Trains!

39.
@gil_zilberfeld
What else?

40.
@gil_zilberfeld
Value
estimation

41.
@gil_zilberfeld
Let’s
estimate
value!

42.
@gil_zilberfeld
It’s not that
simple

43.
@gil_zilberfeld
Liz Keogh’s complexity model
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.

44.
@gil_zilberfeld
Let’s
estimate
complexity!

45.
@gil_zilberfeld
History is
your friend

46.
@gil_zilberfeld
Small,
same-size
batches

47.
@gil_zilberfeld
Let’s break it
down!

48.
@gil_zilberfeld
A few more
things…

49.
@gil_zilberfeld
Assume you
are ignorant

50.
@gil_zilberfeld
Write them
down!

51.
@gil_zilberfeld
“Ignorance is the single
greatest impediment to
throughput.”
Dan North
https://dannorth.net/2010/08/30/introd
ucing-deliberate-discovery/

52.
@gil_zilberfeld
Let’s plan
experiments!

53.
@gil_zilberfeld
We don’t need no stinking estimates!
ANY QUESTIONS?
You can find me at:
@gil_zilberfeld
http://www.GilZilberfeld.com
http://www.EverydayUnitTesting.com