Classical Engineering Vs. Software Engineering

Seeing that Classical Engineering strongly relies on theories of mathematics and rules of God (Physics) hence it is always referred to as ‘good practise’ . How far is Software Engineering from using same ‘best practice’ of Mathematics ?Is there a mathematics of Software Engeneering that can play a role similar to the mathematics of other engineering disciplines?
To what I understand, Software Engineering can never reach the level of Classical Engineering as in usage of ‘Best Practise’ because of several reasons,
-ever changing technology
-different view of same problem
-different solution for same problem
-not best practise available
-lack of standards