Estimation is doable statistically. You can estimate 100 small things with reasonable accuracy, if you work in familiar terrain. That's why scrum an similar tend to work reasonably well for seeing if you are going to hit some iteration deadline etc.
BUT you can't estimate a huge software project up front, because you can't break it into 100 small things up front and it's not usually not familiar terrain before it started. You might be forced to give an estimate up front in order to get a deal, but it's all business theater.
BUT you can't estimate a huge software project up front, because you can't break it into 100 small things up front and it's not usually not familiar terrain before it started. You might be forced to give an estimate up front in order to get a deal, but it's all business theater.