8. typical questions to be
answered
"when will it be finished?"
"when do you have feature X ready?"
"what does it cost?"
8
9. abstraction
need to know about cost to make decision
need to know some numbers to make a plan
customer value?
how can we do it?
how can we do better?
9
11. time vs. effort:
your mileage may vary
time, as in effort of a task, can not be compared
between people
individual productivity may vary
duration depends on lots of factors: resources, task-switching
requirements get stale
11
12. „Work expands
so as to fill
the time
available for its
completion.“
Parkinsown‘s Law
Cyril Northcote Parkinson, 1955
12
13. estimates are muda (waste)
a number has no intrinsic value for your software
Lean: „...any human activity that absorbs resources but
creates no value.“
Principles behind the Agile Manifesto: „Simplicity – the art of
maximizing the amount of work not done – is essential.“
13
17. gaming the system
People turn estimates into targets. Meeting the target
becomes the de facto goal and the de facto method. Meeting
needs fades in priority.
People construe estimates as promises. No one can predict
the future, but many people treat estimates as guarantees.
Failed predictions fan blame. Trust and openness suffer.
http://www.estherderby.com/2012/03/estimating-is-oftenhelpful-estimates-are-often-not.html
17
19. Lake Wobegon effect
aka Illusory Superiority
aka „above average effect“
people misestimate their own ability
19
20. survivorship bias
„... is the logical error of concentrating on the people or things
that "survived" some process and inadvertently overlooking
those that did not because of their lack of visibility.“
look at all your projects
even those, which didn‘t happen
20
23. people are already doing this!
story count gives a more stable prediction than story point
velocity
by Vasco Duarte using Scrum (@duarte_vasco)
various different projects
http://bit.ly/NoEstimatesProjectsDB
23
28. abstraction
use value as primary decision criteria
be better at executing, delivering – the in comparison to the
real world, not some plan
arbitrary plan
cost-driven decision
ignore youre potential
28
30. simple!
1.
select the most important
part of work that has to be
done
2.
break it down into small
chunks (risk neutral,
commitable...)
3.
deliver it
4.
iterate and refactor
(by Vasco Duarte)
Photo: mtshaw, CC-by via flickr
30
31. observe and predict
observe & measure
think about your indicators
do not put guesses in
predict the future
31
33. self-regulating prediction
number of stories instead of arbitrary guess
size of stories may change over time
observed outcome changes -> changes prediction
33
48. Wrap Up
(6)
Guessing + Estimates are bad
value and cost are not related
focus on value, focus on better delivering, gain trust
stop estimating
look at your process to get #BeyondEstimates
48