We've ended up with non-linear weighing of our points. I worry this makes reporting velocity data erroneous. Background:
- A fairly traditional deck is used:
?, 0, ½, 1, 2, 3, 5, 8, 13, 20, 40, 100, and ∞
- Only the low end of the scale is ever used for story estimates, we rarely go over 5 points and only had one thirteen-pointer.
The point value is inconsistent across stories of different size. That is, one-pointers use "lighter" points and eight-pointers use "heavier" points:
1p: add tooltip text to a couple of icons; format date&time strings
3p: create new user role and specify their permissions; automatically create a new case in CRM whenever certain actions are performed
5p: watchlist functionality; filtering functionality on several facets
8p: integrate with a third party provider and introduce a persistence layer to cache their responses
In a textbook scrum
1x 8p and
8x 1p should require same effort, in fact this is exactly what I'm trying to achieve! However in our estimate examples provided, "integrating with a third party" is a lot more difficult than "adding a tooltip... 8 times". So in our sprint planning
1x 8p ≠ 8x 1p.
How can our team break the "anchoring" to this estimating practice? What's the best way to flag up and approach this concern?