I am terrible at estimating.
But I take comfort from the fact that you’re terrible at estimating too.
Welcome to Development that Pays
My name is Gary Straughan
And welcome back to this “mini-series” on Agile Estimation and Planning.
If you missed the first episode
there's a link here that will bring you you automatically right back to this point.
It’s a while since we’ve seen the Lego team.
Let’s bring them back in,
Our hero, the developer in blue
Is working on a brand new feature.
Not an improvement to an existing feature.
A brand new feature.
A feature that - with a bit of luck - will be a game-changer for the business.
And then it happens.
A sequence of events…
that you might just recognise.
The Boss asks the Product Owner a question:
“When will it be ready?”
The Product Owner seeks out the blue developer.
And asks him a question:
“When will it be ready?”
The Blue developer thinks about it for a moment and says...
We’ll come back to that conversation in a moment.
This is Danny Kahneman
Nobel Laureate, no less.
Early in his career, he was part of a team working on a new textbook
- a new university curriculum.
A year in, and the project was going well.
Kahneman had the idea of asking the team a question.
The question was, more or less
“When will it be ready?”
He didn’t ask the question in open forum;
Each of the team wrote their answer on a piece of paper.
When Kahneman read the responses
He found they were in broad agreement
Everyone thought it would take 18 months to 2.5 years to complete the project.
Now, one on the members of the team was the Dean of the School of Education.
And it occurred to Kahneman to talk to him about the progress of the project
He asked him a very interesting question.
He asked if he could think of other teams that had done what what this team was attempting
And the Dean said that he could
He could think of several teams that had gone through a similar process.
How did they get on?
The Dean thought about it.
He realised that about 40% of the teams had failed.
And those that succeed? How long did it take them?
The Dean couldn’t think of any that took less than 7 years.
All of the teams that had succeeded had taken between 7 and 10 years.
(Remember, the Dean had estimated 18 months to two and a half years.)
How interesting, thought Kahneman
The Dean had all the information he needed to make a much better estimate.
But he 'd been wildly optimistic
Kahneman went on - with long-time collaborator Amos Tversky -
to study this effect in detail.
And in 1979 they proposed the Planning Fallacy.
As Wikipedia puts it:
“a phenomenon in which predictions about how much time will be needed to complete a
future task display an optimism bias and underestimate the time needed.”
So when the Boss asks the Product Owner “When will it be ready?”
And the Product Owner asks the Developer “When will it be ready?”
The answer that the developer gives is high likely to be wrong.
It’s likely to be far too optimistic.
Even if the developer is aware of similar tasks that have taken longer.
And even if the developer is aware similar tasks he has done himself
that have taken longer
I know from my own experience that I often think that I’ll finish something
“by the end of the day”...
Only to release that most of the afternoon will be taken up with meetings
Or I’ll be side-tracked by a bug on an existing feature.
Or something that should have been quick and easy
actually takes ages.
So this sequence of questions is, at the very least, not helpful
Just stop for a moment and think about how you feel about this situation.
Perhaps you think that this question is more than reasonable.
That you need some measure of predictability to do your job.
Or perhaps your in this position - the Product Owner.
and you’re feeling just a little bit insulted,
because you’d never ask a developer for an estimate - at least, not in this way.
Or perhaps you’re thinking something else.
If so, I’d love to know what it is.
Let me know in the comments below.
If this situation is a problem, what is the solution?
Is there a way to give each of these people what they need?
I’m not sure… but we’ll take a step in that direction in the next episode.
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For a new episode every Wednesday.
I look forward to seeing you next time
Cheers for now.