they tend to be very accurate
Accuracy in the calculation process is the easy bit .. we can all be accurate.
However, what sets the sheep apart from the goats is the work (and accuracy) which does, or does not, go into
(a) obstacle definition
(b) operational commonsense
In all cases, the operator's procedure (or general operating procedures) should define just what is done when. Otherwise it all smacks of Keystone Cops.