By: Jon M Quigley

Silver  Bullet? NOT!

There is no perfect solution to estimating.  We can try to read the tea leaves, consult the oracle or use of a divining rod.  These are still estimates and have limitations.   Story points use proportional mechanisms for estimating, so there must be some foundation from which to work.  Since story points are proportional and not derived in terms of actual hours, we are never deluding ourselves that the estimates are anything more than approximations or wishful thinking or even hope.  Establishing and articulating duration in terms of hours and days can lead people, especially those who see the schedule, to falsely conclude that the duration is not an estimate but something more tangible – like facts or certainties.  Story points are unit-less, there are no minutes or hours associated.

Besides the lack of definitive duration, what is the benefit of using story points to estimate?  What is  the downside?  How can you determine ETA (or estimated time of completion)?