so my question is, what's the use of class modeling? Is it better for us to do code before doing class diagramming?

Next time you drive over a bridge, or get in an airplane, or (god forbid) go under the knife for an operation, ask yourself if you're OK with the engineer/pilot/doctor doing the equivalent.

Programming chops....creativity....great tools......none of them will save anyone if a system hasn't been designed properly.

The only way developers can get other people to recognize us as professionals is by acting like professionals.

Kevin