Comment by netghost
1 month ago
I worked on a product that was built around planning an estimation with ranged estimates (2-4h, 1-3d, etc)
2-12d conveys a very different story than 6-8d. Are the ranges precise? Nope, but they're useful in conveying uncertainty, which is something that gets dropped in any system that collapses estimates to a single point.
That said, people tend to just collapse ranges, so I guess we all lose in the end.
> 2-12d conveys a very different story than 6-8d.
In agile, 6-8d is considered totally reasonable variance, while 2-12d simply isn't permitted. If that's the level of uncertainty -- i.e. people simply can't decide on points -- you break it up into a small investigation story for this sprint, then decide for the next sprint whether it's worth doing once you have a more accurate estimate. You would never just blindly decide to do it or not if you had no idea if it could be 2 or 12 days. That's a big benefit of the approach, to de-risk that kind of variance up front.
> you break it up into a small investigation story for this sprint, then decide for the next sprint whether it's worth doing
That's just too slow for business in my experience though. Rightly or wrongly, they want it now, not in a couple of sprints.
So what we do is we put both the investigation and the implementation in the same sprint, use the top of the range for the implementation, and re-evaluate things mid-sprint once the investigation is done. Of course this messes up predictability and agile people don't like it, but they don't have better ideas either on how to handle it.
Not sure if we're not enough agile or too agile for scrum.
That's definitely one way of doing it! And totally valid.
I think it often depends a lot on who the stakeholders are and what their priorities are. If the particular feature is urgent then of course what you describe is common. But when the priority is to maximize the number of features you're delivering, I've found that the client often prefers to do the bounded investigation and then work on another feature that is better understood within the same sprint, then revisit the investigation results at the next meeting.
But yes -- nothing prevents you from making mid-sprint reevaluations.
If you measure how long a hundred "3-day tasks" actually take, in practice you'll find a range that is about 2-12. The variance doesn't end up getting de-risked. And it doesn't mean the 3-day estimate was a bad guess either. The error bars just tend to be about that big.
If a story-sized task takes 4x more effort than expected, something really went wrong. If it's blocked and it gets delayed then fine, but you can work on other stories in the meantime.
I'm not saying it never happens, but the whole reason for the planning poker process is to surface the things that might turn a 3 point story into a 13 point story, with everyone around the table trying to imagine what could go wrong.
You should not be getting 2-12 variance, unless it's a brand-new team working on a brand new project that is learning how to do everything for the first time. I can't count how many sprint meetings I've been in. That level of variance is not normal for the sizes of stories that fit into sprints.
3 replies →