Plastic Products is a small company that specialized in the production of plastic dinner plates until several years ago. Although profits for the company had been good, they have been declining in recent years because of increased competition. Many competitors offer a full range of plastic products, and management felt that this created a competitive disadvantage. The output of the company's plants was exclusively devoted to plastic dinner plates. Three years ago, management made a decision to add additional product lines. They determined that existing idle capacity in each plant could easily be adapted to produce other plastic products. Each plant would produce one additional product line. For example, the Atlanta plant would add a line of plastic cups. Moreover, the variable cost of producing a package of cups $($one dozen$)$ was virtually identical to that of a package of plastic plates. $($Variable costs referred to here are those that change in total as the units produced $.$change. The costs include direct materials, direct labor, and unit$-$based variable overhead such as power and other machine costs.$)$ Since the fixed expenses would not change, the new product was forecast to increase profits significantly $($for the Atlanta plant$).$

Two years after the addition of the new product line, the profits of the Atlanta plant as well as other plants$)$ had not improved in fact, they had dropped. Upon investigation, the president of the company discovered that profits had not increased as expected because the so$-$called fixed cost pool had increased dramatically. The president interviewed the manager of each support department at the Atlanta plant. Typical responses from four of those managers are given next.

Materials handling: The additional batches caused by the cups increased the demand for materials handling. We had to add one forklift and hire additional materials handling labor.

Inspection: Inspecting cups is more complicated than plastic plates. We only inspect a sample drawn from every batch, but you need to understand that the number of batches has increased with this new product line. We had to hire more inspection labor.

Purchasing: The new line increased the number of purchase orders. We had to use more resources to handle this increased volume.