As we have seen in the earlier chapter, it doesn’t make sense to map story points with time just because they are not the same thing. It’s like comparing apples with oranges. Briefly following problems happen as we map story points with time:
- During the planning-poker exercise, the focus of the conflict in story points happens to be time estimates among multiple developers instead of improving their shared understanding of the need through poker exercise.
- It becomes difficult to know how much work the team is accomplishing in each sprint as size of the work doesn’t get measured through story point estimation, but the time does.
Some teams may be okay with these problems and still may want to get ahead with mapping a story point with time. However some teams may want to fix that.
In my experience, the teams which are already mapping a story point with time, it becomes difficult to unlearn the mapping even if the team wants to.
At the same time, for teams which begin with a fair understanding that story points are all about size, complexity and uncertainty/risk, a question eventually comes if there is any mapping between a story point and time.
In one of these teams, instead of story points, we began with the idea of T-shirt size based relativeestimation.
Rather than using numbers in the fibonacci series, here, Items are classified into t-shirt sizes: XS, S, M, L, XL.
In the planning-poker exercise instead of using fibonacci numbers, we used T-shirt sizing. Surprisingly everybody got the idea without any problems just because T-shirt sizing seems to be all about size and not about time.
These T-shirt sizes can further be mapped with story points. So XS becomes 1-2, S becomes 3, M becomes 5, L becomes 13 and XL becomes 20. Anything beyond, has to be broken down further.
I find it helpful to use T-shirt sizing instead of numbers as everyone in the team seems to get the message clearly.
More on Story Points and Agile Estimation
This post is a part of a blog post series on story points and agile estimation. To read rest of the posts on the subject, please navigate to All About Story Points and Agile Estimation Series.
[…] The T-shirt method is also used to evaluate the complexity of an issue but it forgoes the concept of having points whatsoever. Engineers simply use T-shirt sizes like S, M, L, XL, and XXL instead of numbers. […]