The Scrumism for this post is one that I’m sure some of the Scrum teams I’ve worked with had gotten tired of hearing me say.
When a Product Owner (PO) is working on a product backlog, he or she pays attention to first getting things identified (at least at an epic level), then getting things in the right order, and then getting the right level of detail in the product backlog items (PBIs) given where they are in the backlog. At the top of the backlog, the PBIs need to be ready for sprint entry, and so you need enough detail for the teams to begin working on the stories. As you go further down in the backlog, less detail is needed, and the story point estimations (or “effort estimations”) get larger since the information is fuzzier. This is by design, and is part of the concept that you want to delay decisions to the last responsible moment so you are making those decisions with the best information available.
Story points estimates, combined with what you know about team velocity, are what allow you to make predictions about a roadmap. The question “do you have enough for an estimate” means different things depending on where the PBI is in the backlog. If it is a story that you want to be in the next sprint, then it should have everything needed for the development team to take it into the sprint. If it is down near the bottom of the backlog, then there needs to be enough information in the PBI for development to understand roughly what the feature is, and can compare and contrast it to other work they’ve done. So the amount of information needed to give an estimate can vary quite a bit. The developers have to get to a point where they feel there is enough information to give a reasonable estimate, though sometimes they just have to say there isn’t enough on which to base a decision and the PO needs to do more work on a PBI. When we ask “do you have enough for an estimate”, development lets us know if they can give story points, or if there is more elaboration needed. I’d ask the question when I felt the discussion on a PBI was slowing, so I could gauge how much more we needed to talk. If the engineer says they have enough – we’re done! Get the estimate recorded and move on.
Remember we constantly groom the backlog, so the estimate is given with the information available at that time.