Part of a series on Making better estimates.
Probably the simplest way of improving your project estimates is to explicitly de-couple duration from calendar. It’s easy to become so involved with estimating the duration of tasks that you forget to account for the actual work calendar.
On a small time scale, estimating in relative complexity and measuring velocity helps with this de-coupling. If your company culture is such that you can expect to spend 10 hours per week in meetings, then your velocity will automatically reflect that – you don’t need to remember to use 30 work hours per week when making calendar projections from duration.
Even with points and velocity, you still need to keep your eye on the large time scale picture. If your estimate for a project indicates you need 30, one-week iterations to complete it, don’t forget to lay those 30 iterations against a calendar of vacations, holidays, conferences, plant shutdowns, or whatever else takes people away from work in order to predict a completion date.
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