We have three primitive sets in this model--raw materials (RAWMAT), finished goods (FINGOOD), and quality measures (QUALMES).

From these three primitive sets, we create three derived sets.

The first derived set, RXQ, is a dense derived set and is a cross on the raw materials set and the quality measures set. We need this derived set in order to define an attribute to hold the quality values for each of the raw materials.

The second derived set, QXF, is a cross on the quality measures and the finished goods. We need this set because we will be concerned with the levels of the quality measures in the finished goods.

The final derived set, RXF, is a cross on the raw materials and finished goods. We need this set because we need to compute the amount of raw material used in each finished good.