Project Management What is the 90 90 rule? March 5, 2026 by Mercier | Leave a Comment The 90/90 rule is a project management technique designed to combat over-optimism in estimating task completion times. It suggests that the first 90% of a project often takes 90% of the time, and the remaining 10% takes the other 90% of the time, highlighting the common tendency to underestimate the final stages of development. Understanding […] Read more ยป