avoid, stave off, ward off, avert, deflect, debar, fend off, eliminate, head off, rid of, more...

necessitate, require

preclude, prevent, forestall, render unnecessary, make unnecessary, more...

to make unnecessary,   render unnecessary,   remove the need for,   be prevented,   eliminate the need,   make superfluous,   remove the need,   reduce the need for,   avoid the need for,   to remove the need