Jerusalem Medical Ltd an Israeli producer of portable kidney dialysis units and other medical products, develops a 4-month aggregate plan. Demand and capacity (in units) are forecast as follows the cost of producing each dialysis unit is $875 on regular time $1, 310 on overtime and $1, 500 on a subcontract Inventory carrying cost is $100 per unit per month There is to be no beginning or ending inventory in stock and backorders are not permitted