default notice period based on grade

Summary:

We have a requirement to default Notice Period based on the value of the employees assignment Grade. Can we achieve this without multiple rules?

Content (please ensure you mask any confidential information):

One of our legal entities has rules on Notice Period. We want to default the Notice period value based on the assignment Grade.

I can do this in VBS with one rule for each grade/notice period condition - but that seems extremely inefficient and not much fun to maintain considering everything else in the rule is identical, just the defaulted value for Notice Period is different. What we really want is just one rule that can check for the Grade and default the notice period accordingly.