The developers discuss each story and come up with an estimate based on their experience. High-level design discussions
take place as developers try to understand the story and discuss different ways of implementing it. In some cases, the
team will not be able to provide a reasonable estimate:
They do not understand the story: the team should be asking more questions to the customer.
The story is too big: the developers don't have a good grasp of the scope. It should be broken down into smaller
They don't know how to do it: they will need to do some research first.
Be careful to avoid analysis paralysis. The first few times the team estimates stories, it may take as long as an hour
to estimate a story. The second story should take less time. Your goal should be to be able to estimate a story in only
a few minutes.
As a rule of thumb, story estimates should not exceed the iteration length based on a pair of people dedicated to the
story. When stories exceed the iteration length, the customer splits the story.