Gunnar Ahlberg - Into software home


Published 2011-05-02 - Stockholm

Why is estimation work still relevant? Many projects do too many estimations.

Isn’t estimation of software development just another waste?

My wife is perfect at estimation. She can estimate exactly what size of jug I should use to save anything. But that is for food. How do we estimate software costs?

Given a budget process for a project, a good estimate of how much cost the project is maybe a good thing. The estimate can provide the product owner in a valuable gauge in how much money do I put in to the project versus the risk versus the possible gains. But all those are highly volatile. The productivity of any group has so many different factors. Just to mention a few, the number of external dependencies, unforeseen technical problems, scope creep, illness, hardware failure.

An alternative would be, just define that this project is allowed to run for a fixed period with a fixed set of people and an infinite backlog of items to accomplish and with a rough estimate in small - medium - large. And then evaluate how many story points was achieved. Give a small item one, medium two and large items four points. Let the experiences from the first iteration become empirical data for the next iteration.

This alternative has lower risk as the possible expense is set in advance. Anything that is not delivered in that iteration can possibly be either left on a backlog. The estimates now disappears and any data can be gathered from empirical data.

Too sad that people miss out on this.

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