Monday 29 July 2013

The Myth of Certainty

I've posted before about "uncertainty" as an indicator for estimation. I have also been reading some blogs & tweets on how estimation is pretty useless. Check out #NoEstimates or have a look at Vasco Duarte's blog.

I can certainly sympathise with the views being discussed. People have an overwhelming desire for certainty. It makes us comfortable. But, what does certainty look like? Some of my colleagues, past and present find that only dates and numbers provide that comfort, in as much as they insist on seeing the number of story points for a project up front.

This is pretty useless in reality, as we are pinning our hopes on something that is not particularly reliable. The first thing Ken Schwaber said at my Scrum training back in 2005, was that "estimates are always wrong".
"So", ask the #NoEstimates tweets, "why do we still do estimation?"

If it is certainty that we crave, we should be looking for predictability. Team velocity was one way the Agile community tried to increase predictability, but that wraps an artificial concept (i.e. points)around measuring output. There seems to be some momentum around doing away with story points altogether.

If a team is focused on delivering value, they should always be giving the customer what they need nice and early. Agreeing the MVP or MMF is a good start. Then the team should be breaking down their stories into chunks that they know they can deliver within a predictable time-frame e.g. 1 day. Because they do this, they know that they can deliver, say, 10 stories a week. It is proven, and predictable.

I am going to watch this debate with interest.

1 comment:

Unknown said...

It is an interesting topic. The desire for certainty and predictability is ultimately the human desire for security in any form. It is a misnomer that numbers give us this. On the other hand, we still need to guide the project and make decisions. So IMO the approach that has worked best for me so far is: have a high level goals, have a plan to get there but don't stick rigidly to it, be ok with uncertainty and give more frequent chances to adjust the direction.