When a company has limited 1. resources it should compute the contribution margin per unit of limited resources to decide which product should receive additional capacity of the limited resources. 2. resources to manufacture products, it should manufacture those products, which have the highest contribution margin per unit 3. direct labor hours available for production, it should manufacture those products with the higher contribution margin per machine hour. 4. machine hours available for production, it is generally more profitable to produce and sell the product with the highest contribution margin per machine hour.