Are we talking logic such as:
if (Item.qty % 2 == 1){Item.accessory("Rack Kit) = ((Item.qty - 1) / 2) + 1;
} else
Item.accessory("Rack Kit") = Item.qty / 2;
The ability to incorporate logic scripting and associate this with items in the Data Matric is definitely an interesting concept. I like rule driven design.
It is impossible to remember every detail in these kind of scenarios like "if I add an odd number of mic receivers I need a rack kit for each pair plus one for the odd receiver".