The product hierarchy stretches from basic needs to particular items that satisfy those needs. A product system is a group of diverse but related items that function in a compatible manner. A product mix (also called a product assortment) is the set of all products and items a particu-lar firm offers for sale. A product mix consists of various product lines. As shown in Table 9.1, a company’s product mix has a certain width, length, depth, and consistency. The table shows these concepts for selected Procter & Gamble products.