About Estimation

Recycling an article I wrote in French in 2010.

Following endless estimation sessions in the project I am working on, I have come to ask myself some questions about this practice.

Why do we estimate? I think an estimation session should have two purposes.

• To share a common understanding of upcoming stories.
• To estimate upcoming work in order to plan the next steps and monitor the evolution of the project.

Who should attend the estimation session? Anyone who can clarify upcoming stories and anyone who will carry these stories to completion.

To improve your estimation session, you can try the following: divide the estimation session into two stages.

1. Understanding upcoming stories.
2. Estimating the work to be done.

Understanding upcoming stories through discussion among project participants is the highlight of an estimation session. The shared vision emerging from these exchanges will facilitate future communications.

Estimating should be more relevant and should be done faster once the stories are well understood. To further facilitate the process, I like to do the following:

1. Print the titles of the stories to estimate on cards.
2. Order and group these cards on a table depending on their evaluated complexities.
3. Associate each groups with an estimate.

And do not forget that an estimate is "An approximate calculation or judgment of the value, number, quantity, or extent of something".

Recommended reading: http://martinfowler.com/bliki/PurposeOfEstimation.html