Estimating work
In Chapter 3, Sprint Planning – Fine-tune the Sprint Commitment, we discussed the traditional Scrum method of breaking PBIs into four to sixteen-hour tasks for the sprint. The reason behind this is that if a work task is small, the team member working on it will have something new to report every day, or at worst, every other day. This visibility into daily status allows for an entire team, then, to jump in and help each other when they can. If you visualize the Scrummage formation in rugby, you can see the similarities, except our Scrum team is huddled around product backlog items, not rugby footballs. Small estimates combined with a daily scrum meeting help the team move the sprint's PBIs together to completion.
When Scrum teams first start out, they focus on planning sprint tasks with lots of detail in order to ensure that they haven't overcommitted, as well as to generate their sprint burndown chart (Chapter 6). Due to the repetitive, sometimes boring nature of planning...