The 90/90 rule captures the notion that (programming project) estimates are wrong, in addition to the Pareto principle. Now if 90/90 is accurate because of unk

The 90/90 rule captures the notion that (programming project) estimates are wrong, in addition to the Pareto principle. Now if 90/90 is accurate because of unknown unknowns, or just because we are all terrible at estimation and planning is debatable;)