The material properties from the material library should be parametrically linked to the parts they are assigned to. If a material is revised to have some properties change, all parts that have that material assigned should reflect the updated properties in the revised material.
We have a material library corresponding to the raw materials we buy. We noticed a mistake in the Y-factor for a lot of steel parts, and we revised the material properties to change the Y-factor. None of our parts that had those materials assigned automatically updated to reflect the new Y-factor. We have to manually go into each part and delete the material assignment and re-assign from scratch to get the new properties. There should be a parametric link which would avoid a lot of this manual labor.