They&#x27;re not useless.  Except sometimes they are.<p>I have to give estimates all the time.  They&#x27;re estimates, but they&#x27;re in the ballpark.<p>But recently, I had to give an estimate for porting some software to a new environment.  I knew it was going to present me with a bunch of obstacles, and I didn&#x27;t know what the obstacles were, or how long each one would take.  <i>I didn&#x27;t even know how many obstacles there would be.</i><p>I didn&#x27;t want to give an estimate for that.  They made me give them one anyway.  I did, <i>but I knew that no reliance whatsoever could be placed on the estimate.</i>  Whereas other tasks, estimates were close to &quot;bet the company on it&quot; solid.