Story Points vs. Story Count

Stephen Connolly's picture

A recent tweet caught my interest:

Now in the interests of full disclosure, this matches my own thinking. I have long suspected that story points are not really a good tool for estimating sprint capacity… but I do think they are a potentially useful tool to help decide if a story has been correctly scoped. 

If you have the team look at the story and they all agree on the story points, e.g. everyone says it’s an 8 or a 13 (if you are using Fibonacci numbers) then that says everyone has a reasonably shared understanding of the story scope. On the other hand, if one person says 2 or 34 then that should trigger a discussion as to why they have an estimate that is different. Typically the reason why is because there are other requirements that should be considered in the story scope.

I also suspect that story points may be a good tool for sprint capacity planning if your stories are big such that you typically have between 1 and 4 stories per sprint. I suspect with small numbers of big stories there will be more variability in story size and thus story pointing might be useful… of course, every team I have worked on has had smaller stories and big stories have ended up being broken down. The typical teams I have been on over the last 10 years have seemed to work on at least 8-10 stories per sprint (focused on a small number of “epics”… but let’s not start that debate!)

Anyway, claims on twitter are not actual evidence… but twitter wasn’t long providing some:

So we have at least one data point and it confirms my bias too!

Confirmation Bias

So how about we fix that by collecting actual results?

Here is my call to action. If you have at least 5 consecutive sprints from the same team, please fill in this form. I will post a follow-up blog post with the analysis once I have enough data!

Stephen ConnollyStephen Connolly has over 25 years experience in software development. He is involved in a number of open source projects, including Jenkins. Stephen was one of the first non-Sun committers to the Jenkins project and developed the weather icons. Stephen lives in Dublin, Ireland - where the weather icons are particularly useful. Follow Stephen on Twitter, GitHub and on his blog.