A company has two manufacturing plants (PA and PB) and three sales stores (I, II, and III). The shipping costs from production centers to the store centers, the manufacturing data with capacity constraints, and unit costs of production, as well as the demands data for the store with sales price and maximum sales constraints, are given below in Tables 2-4. Cost of holding a unit of inventory is 1, while the maximum storage in the company (either at plant level or store) allowed is 75 units. TABLE 2 SHIPPING COSTS Store Plant I II PA PB 36 8 EN III 7 3 4 TABLE 3 MANUFACTURING DATA Plant A (PA) Plant B (PB) Period Unit Cost (E) Capacity Unit Cost (E) Capacity 1 7 180 6 190 2 9 170 10 195 TABLE 4 DEMAND DATA Selling Price Maximum Sales Period I II III I 11 III 1 2 20 18 17 110 190 145 17 20 22 145 295 155

a. Identify the objective function to maximize, i.e., Z = Total Revenues - Total Costs.

b. Identify and formalize in Excel the various constraints.

c. Build in Excel, using the Simplex LP Solver the optimal production schedule over the two periods.