I&#x27;m in an organization that uses this method, and I don&#x27;t think it helps. I believe our &quot;optimistic&quot; metric is supposed to be something like &quot;We have a 10% chance of hitting this goal,&quot; our &quot;realistic&quot; metric is supposed to be something like &quot;We have a 50% chance of hitting this goal&quot; and our pessimistic is &quot;We have a 90% chance of hitting it&quot;. (Or something like that. I don&#x27;t remember the exact values off the top of my head.) But what happens is the engineers estimate what they think it will take, claim that&#x27;s the &quot;realistic&quot; option, then add or subtract some percentage from that for the pessimistic and optimistic values. Nobody really understands how (or if) it&#x27;s supposed to work, so the estimates are still bad.