simulating machining with normal or bump maps

does anyone know how to simulate machining process using normal or bump maps? (i suppose this approach could be easier than destructible meshes)
i just dont know how to create these maps evolving over time and having control over its size (or geometry) when it is being developed.
any help would be greatly appreciated

I don’t think that would work, but you could probably do that with Morph targets

Look at tutorials for Snow Deforming, Material Deforming, etc.