>The team I worked with tried something similar where we broke down tasks into cards, where each card represented something that should take about a day to comp

>The team I worked with tried something similar where we broke down tasks into cards, where each card represented something that should take about a day to complete. This is almost basic probability theory. http://en.wikipedia.org/wiki/Central_limit_theorem http://en.wikipedia.org/wiki/Central_limit_theorem Estimations could be viewed as random samples with some distribution. The total is the sum of individual estimations. The sigma of the total is less than max(single task estimation sigma) * sqrt(number of tasks). 30 estimations with 0.5 day sigma gives us total sigma 0.5 * sqrt(30)=3 and 96% confidence bounds of (30 - 3 * 2)..(30 + 3 * 2) work days. Most of the time you will see 30+-3. ;) Unless you find a task that does not break into one day. Say, with low estimate "tomorrow" and high estimate "half a year". ;)