Chris James

Developer and other things

Estimates

Published on 29 December 2015

Why do developers whine about doing estimates? All the business wants is just some kind of assurance that their important project will be done by a given date. What’s the big deal?

Let’s be clear here, estimates are always wrong

That’s not the worst of it. When you lock your development team in a room for a few hours to try and estimate 100 stories you are now suddenly back in the waterfall world. You are committing yourself to a set piece of work that cannot change.

Which is what I thought as an industry we had got past. These are inarguable facts about software development

  • Priorities change
  • Knowledge (about a system being developed) changes
  • Teams change (they get better, usually)

Not only is it impossible to say “40 features will be delivered by April”, but you shouldn’t want to either!

In X weeks time, you will have a better understanding of what you want and the development team will be better equipped to help you make those decisions. Upfront estimations take you away from this.

The estimates I do like

  • A finger in the air estimate of a bunch of high-level features can of course be given. These are ok because everyone knows that they’re vague and subject to change
  • Relative weighting of features. This is actually the only estimate that’s important because it helps the business make a decision based on a sense of reality.

Estimation sessions

“Estimation sessions” where a gigantic pile of stories are dropped at the feet of developers locked in a room for a few hours, points to big flaws in your process.

It doesn’t acknowledge that change happens

Only when you actually start doing the work do the real problems you’re facing become clear. There will be stuff you missed which will effect your to-the-day timescales.

It implies you’re doing mini waterfall, not agile

I am often astonished when I see these huge piles of cards. Where have they come from? What happened to the principles of lean-ness and doing just the work you need and then moving your priorities as and when you need them?

You have done the “analysis” stage of waterfall already it seems. You have looked into your crystal ball and worked out all the features that your customers need.

The software project fallacy

You have a deadline and I understand this. I hope you understand that if your software is worthwhile that it will still need work on it after your deadline. If it’s not worthwhile, why are we building it?

At the very least it will need maintenance but if your software is actually good, by setting a hard deadline you are really shooting yourself in the foot.

People often forget that what’s really good about software is you can change it. The industry has dedicated so much energy in trying to make software malleable, yet so often we are poor at selling this to the people paying our wages.

By setting hard deadlines you are creating a precedent that you know what your customers want and that their needs never change. Quite the claim.

Go back to basics

Build, measure, learn over a small handful of the most important features. Discover what features are actually important and get it right. Everyone will learn about the product and you may develop something completely unexpected.

If you do this in a collaborative way with the business you will get out of the mindset of software being a static thing that you make and throw away.

If the parties engage together they can make something better. The software development team is not seen as a cost-centre but an asset that can actually respond to changing needs.

Summary

Fine-grained estimations disregard many of the good principles around lean, agile software development. Instead of trying to predict when a set-in-stone list of features will be done, acknowledge the unknown of business needs and if you create a truly collaborative team you can build a better product than you imagined.

You cant escape deadlines. But you should be focusing your efforts on building a team that works hard at becoming efficient at writing maintainable, useful software by working with the business/customers and responding to changing needs.

There is some interesting debate around this on twitter