Bertallo Classic produces tomato sauce at five different plants. The tomato sauce is then shipped to one of three warehouses, where it is stored until it is shipped to one of the company’s four customers. The following inputs for the problem are given in the file P06_61.xlsx:

■ The plant capacities (in tons)

■ The cost per ton of producing tomato sauce at each plant and shipping it to each warehouse

■ The cost of shipping a ton of sauce from each warehouse to each customer

■ The customer requirements (in tons) of sauce

■ The fixed annual cost of operating each plant and warehouse

Bertallo must decide which plants and warehouses to open, and which routes from plants to warehouses and from warehouses to customers to use. All customer demand must be met. A given customer’s demand can be met from more than one warehouse, and a given plant can ship to more than one warehouse.

a. Determine the minimum-cost method for meeting customer demands.

b. Use SolverTable to see how a change in the capacity of plant 1 affects the total cost.

c. Use SolverTable to see how a change in the customer 2 demand affects the total cost.

d. Suppose that each customer’s demand must be met from a single warehouse. Solve the problem with this restriction.