Story points aren't working - what can I do?

If your team uses story points (SP) and are questioning their value, or they see value in them but are struggling to accurately estimate their sprint capacity (or likelihood of hitting delivery milestones) using them, there is a simple thing you can try without having to change anything about how you work:

Count stories (SC) in addition to tracking the SP velocity.

Once you have a few sprints of data, do the following:

1. Put your team’s SC and SP velocity over the past 6–12 sprints in a spreadsheet, one row for each.
   
   
2. Use the average (mean) and stddev (standard deviation) functions on both rows, and divide the second number by the first. This gives you the coefficient of variation (COV) — the volatility of the data.
   
   
3. The row with the lowest COV is least volatile, thus the most predictable. If this row is the SC data then SC is a better predictor of your team’s capacity than SP.

You can now make an informed decision about a simple first step to improving your predictability — use the estimation unit with the lower COV for capacity planning and forecasting. No conjecture or process change required.