There are two questions inherent to this thread. But let's go step-wise:
I have this formula in which I want to sum items (Description) that contains ANY of the strings in the C16 to C17 range:
= SUMPRODUCT( SUMIFS(Value; Description; "*"& C16:C17 &"*") )
This formula however, double counts any rows that contain BOTH strings.
Any idea on how to get around this?