I have recently come across this situation:
- user stories are estimated using story points
- timebox planning session has taken place and everything is agreed on
- timebox (three weeks) is in week three
- team decides a story has been estimated too small but still thinks that they can get it done in the timebox
However, the team wants the original estimated story point value to be increased, say from 5 to 13 to reflect how much effort is now involved.
My own feeling is that the story points have been estimated as a best guess to aid with planning. Now that the timebox is under way, I think the team questions if the story can still be fully completed within the timebox. We should not re-estimate it. However, it may be useful to keep a note for future estimating or planning sessions for similar items.
The culture is that story points are used as justification of what team members contribute to the timebox, and therefore always get mapped to days:
- 3 = 1 day
- 5 = 2 days etc
Personally, I don't agree with this approach and re-estimating the story seems another symptom of this issue.
Normally, if the team has committed to delivering 100 points based on previous velocity and the client asked to add 8 points during the timebox we would say no as the velocity is 100, the timebox is fixed and we couldn't possibly add more.
Likewise, it should not then be OK for the team to effectively increase the velocity to 'fix' a perceived estimation problem.
I guess my question is: What would be recommended practice for re-estimating a story mid timebox and what are the pros and cons of the approach my team wants to take?
Note, I am not the project manager in this team.