How to estimate delivery date with unidentified tasks
Given a software project which is complete when all of its
deliverablesare delivered, in which each
sub-deliverables, in which each
tasksassigned to it
It is possible that not all
taskshave been identified at the start of the project, and that some
sub-deliverablesrequire many more
tasksto be completed during the course of the project before the
How does a project manager accurately account for these unknown
tasksin the beginning, to provide a more accurate approximation of project completion date?
By estimating iteratively.
Look into the cone of uncertainty.
At the start of the project, the amount of uncertainty is high, and the cone wide. Thus, your estimate would be 'between 2 and 6 months'.
Partway through, the uncertainty lessens and the cone thins. One month in, the cone becomes '3 to 4 months'. 3 months (12 weeks) in, it becomes '13-14 weeks'.