Forecasting software?

[jenk]

David Gilbert discussed applying hurricane forecasting methods to software. One thing that caught my eye, that he says he has "NEVER seen [in] any model of software planning", is "The Cone of Uncertainty".

Starting at the point where the storm is now, following roughly along the predicted path of the storm, is an ever expanding cone. This cone represents where, given all the information currently available, the storm MAY go if something in the model changes. [...T]his is the part of the model that forecasters talk about the most, and encourage everyone to pay the most attention to. This is the part of that model that takes into account Risk and Ambiguity.

Shipping software is ambiguous, and taking that into account is a good thing. But (to continue the metaphor), project management is all about getting to a particular destination at a particular time; tracking a hurricane is trying to see where & when it will arrive.

But perhaps there's room for both. Yes, aim for the goal. But also track the "cone", and forecast how far off track the project may currently get...