let 
    Source = (anySN as nullable any) as text => let
        TrimSN = try Text.Trim(Text.From(anySN)) otherwise "-36002",
        MarkNulls = if (TrimSN = null) or (TrimSN = "") or (TrimSN = "0") then "-36001" else TrimSN,
        Normalize = try Text.Upper(MarkNulls) otherwise "-36002"
    in
        Normalize 
in 
    Source