At the Agile Specification, BDD and Testing Exchange last month in London, Dan North spoke about selling behaviour driven development to the business. He put forward a relatively controversial idea on estimation: treat all stories as equal. Estimate each story as size 1 and just be done with it. Although this idea might seem overly simplistic, I find it really appealing.

On my current software project, we find this concept more than appealing - we find it works!

Every story starts out life as a 1-point story and should be able to be turned around in 8 hours from start of specification to customer acceptance.

If it turns out the story took more time, we run a quick post-mortem to find out why and then add a new rule to one of our "yardstick" documents (we have one for specification, one for development, one for testing). Now we have a better yardstick (get it?) for analyzing and possibly rejecting a story.

Yardstick documents can also have quality concerns in them as well in order to deal with "weak" stories that are certainly 1-point or less, but produce poor results. An example of this is a story with no behaviorial tests other than a "happy path" specified. This can certainly be turned around in time, but the results are likely to be bad.