There is an enterprise methodology that increases precision of project estimation.

1. Guess the order of magnitude of the task (hours vs days/months/years)

2. Add known planning overhead that is almost order of magnitude more.

Example: if we guess that task will take 30min, but actually it took 60min - that’s 100% error (30min error/30min estimate).

But if the methodology is used correctly, and we spend 2h in a planning meeting, same estimate and same actual completion time results in only 20% error, because we increased known and reliable part of the estimate (30min error / 2h30min estimate)