Ok, simple task, used to do it manually by guesswork mainly ;)

I have a block of metal, rough-sawn on two edges, say i need to make this exactly 50mm wide from these two edges.

Square and clean up one edge by doing a facing pass on it but remove just enough to clean it,
Zero the Z axis on the base of the vise or whatever the part is held in,
Rotate the part and run a pass or passes to arrive at Z50.00

Is that a reasonable plan for a seemingly simple task?