[KineticLensman]

> The amount of time/effort required to create a reliable estimate would probably double the cost of the completed project (ie, even after taking into account the overshoot on the informal estimate). The number of failed projects as a percentage of all projects would fall, but less projects would even start.

Another way of looking at it is that for most projects, the uncertainty in the estimate only reaches zero at the end of the project (when you know, hopefully, how much was actually spent). If a project is lucky, the initial uncertainty is low and reduces monotonically over time as the project progresses, so that the estimates gradually converge on the real cost.

[steveBK123]

And the unlucky projects are the ones so poorly planned that the uncertainty actually grows over time as new issues are uncovered.

[doctor_eval]

Yes.

It’s like the old saying:

“Plans are nothing. Planning is everything”.

The work of estimating the effort for a project is worthwhile, even though the resulting estimate is worthless.