An air conditioner manufacturer wants to construct aggregate planning for the next year. The demand for air conditioning has a seasonal pattern as seen in the table below.

Month	Jan.	Feb.	Mar.	Apr.	May	Jun.	Jul.	Aug.	Sep.	Oct.	Nov.	Dec.
Forecast (unit)	600	400	400	1600	2400	3200	4000	2400	1200	400	400	600

The company has gathered the following cost data:

Beginning workforce	6 workers
Initial inventory	0
Ending inventory	0
Subcontracting capacity	unlimited
Overtime capacity	1500 units/month
Production rate per worker	120 units/month
Regular wage rate	$12 per unit
Overtime wage rate	$20 per unit
Subcontracting cost	$25 per unit
Hiring cost	$150 per worker
Firing cost	$280 per worker
Holding cost	$3 per unit/month
Backordering cost	$15 per unit/month

Calculate the total cost of each aggregate planning strategy below. Which strategy would you recommend?

Plan A - Chase demand

Plan B - Level production with overtime and subcontracting, as needed,

Plan C - Level production with backorders as needed

Plan D - Optimum strategy