Is there a word that means "make someone (or something) redundant"?

For example, by improving some system, some function is now redundant. So the improvement XXX that function.

Solution 1:

If you aren't replacing the old function by a new one (i.e., a function is no longer required) then you may prefer obviate, as in "this feature obviates the need to call XXX" or "new procedures obviate the need for a dedicated XXX department."

Or obsolete may be used as a verb, like "this feature obsoletes the XXX function" – although I'd definitely avoid calling a person obsolete.

But if you can say "XXX is now called automatically when needed," I'd go with that.

Solution 2:

I would say that the new supersedes the old.