This is a guest blog post by my colleague: Chris Waggoner. Enjoy!
Estimation of time and effort until you’re done is one of those things that every inquiring manager wants to know. In an effort to provide “accurate” estimates, companies and people spend countless hours generating list of task and debating the duration of each task. When it comes to developing software these estimates are rarely correct and often grossly wrong. The estimates are wrong because in building software that we are often building something that has never been built before. When we find ourselves being pressured to estimate something we’ve never done we tend to SWAG (PMI for Sophisticated Wild Ass Guess) the answer in man-days and/or hours without understanding or knowing all the potential variables in play. Here in lies the problem with traditional software estimation methodologies: within a short amount of time spent there are diminishing returns on effort versus value. That is to say, early in the traditional process the value of spending more time estimating doesn’t provide a higher certainty of when we will be done.