Month,Demand $,$ Regular Time Capacity,Overtime Capacity,Subcontracting Capacity

January,"$1,400","1,600",0,0$

February,"$1,600","1,400",0,0$

March,"$1,600","1,600",0,0$

April,"$1,700","1,600",0,0$

May,"$2,200","1,700",0,0$

June,"$2,100","2,200",0,0$

July,"$1,700","2,100",0,0$

August,"$1,700","1,700",0,0$

The president of Hill$$ Enterprises, Terri$$ Hill, projects the$$ firm's aggregate demand requirements over the next $8$ months as$$ follows:

January

$1$ comma $400$

May

$2$ comma $200$

February

$1$ comma $600$

June

$2$ comma $100$

March

$1$ comma $600$

July

$1$ comma $700$

April

$1$ comma $700$

August

$1$ comma $700$

Her operations manager is considering a new$$ plan, which begins in January with $200$ units of inventory on hand. Stockout cost of lost sales is $$$$100$ per unit. Inventory holding cost is $$$$25$ per unit per month. Ignore any$$ idle$-$time costs. The plan is called plan A$.$

Plan$$ A: Vary the workforce level to execute a strategy that produces the quantity demanded in the prior month. The December demand and rate of production are both $1$ comma $600$ units per month. The cost of hiring additional workers is $$$$55$ per unit. The cost of laying off workers is $$$$80$ per unit. Evaluate this plan. $($Enter all responses as whole numbers$.)$

$$Note: Both hiring and layoff costs are incurred in the month of the change. For$$ example, going from $1$ comma $600$ in January to $1$ comma $400$ in February incurs a cost of layoff for $200$ units in February.