Use the information in Table $10\mathrm{.}1.$ Which one of these trade$-$offs works to your greatest advantage in terms of reducing costs over the entire planning period?

Table $10\mathrm{.}1$

Bart Incorporated manufactures rotary air fans and uses a production$-$planning horizon of one$-$half year. It allows for regular time, part time, overtime, and subcontracting production to meet the demand but no more than $12$ units may be made by each of these methods. Both anticipation inventory and backorders are allowed. The beginning $($or current$)$ inventory is $20$ units. Their first attempt at a sales and operations plan has resulted in the following.