Milena Mastrasso

Software estimation is the ghost of the process, always is difficult to estimate how much time it will cost, you can do it in different ways, with different techniques, by intuition, by the quantity of code lines or story points, by experience of someone or because you compare the project with other projects.

In the last meeting of agiles@bsas we were talking about software estimation in agile projects, we were discussing some different techniques. One of them is known as Planning Poker and I found it very interesting and let me explain why.

Starting the Estimation Process

To start the process someone tell what are a user story about, then all the people think which is the cost of this story and tell to the others. Up to this point all be right excepting for something that I take notice after some projects: the first person who say which is his estimation influence the decision of the others.

Imagine that instead of saying which is the estimation of each member you write it in a peace of paper and facedown and then all the papers turn over, no one knows what is written in the other papers, so there is no influence.

Planning Poker

The planning poker is a funny way to do the paper games but using a deck of card like this one:

You can notice that there aren’t all the numbers. This is because the objective is that estimation is not accurate, so each card must be bigger enough  than the previous.

So, after the user story explanation, each member put his card face down, and all together turn over. If there are lot of differences between  the estimations they discuss his opinions and re-estimate. If there are agreement the estimation is over.

Some considerations

• If a user story needs one hundred card it means that is too big or is incompressible, so the client or the Product Owner must divide it to decrease the complexity.
• When someone put a zero card it means that this task is already done or should take no more than a few minutes of work.
• The cup means that the team member is tired to think and need a break.
• The question mark card means “I have no idea”. If this card is used too often, the team needs to discuss the stories more and try to achieve better knowledge spread within the team.