A company has to plan a production schedule over a four-period horizon, where the re- quirements by period are 20, 10, 40, and 30 units, respectively. Costs for holding a unit of inventory are h =3, h = 2, and h3h4 = 1. No shortages are allowed. The produc- tion costs are given in Table 6. These costs are assumed to be constant for the given range of P. Maximum production for each period is 35 units. The initial inventory is zero and the final inventory is to be zero as well. Maximum storage capacity is 5 units for period 2 and period 3. TABLE 6 MARGINAL PRODUCTION COSTS Period of Production Range of 1 2 3 4 Production 1 P8 4 6 6 3 9s Ps 17 5 10 8 5 18 P, 25 6 12 10 7 36 s P s 35 8 14 12 10 Source: Lynwood A. Johnson, Douglas C. Montgomery, Operations Research in Production Planning, Scheduling and Inventory Control, Table 4.5, p. 208, Copyright 1974 by John Wiley and Sons, Inc.