Darind) & Subcontracting2. A manager would like to know the total cost of an aggregate production plan that meets the forecasts below using a steady regular production rate of 200 units a month, a maximum of 20 units per month of overtime, and subcontracting as needed to make up any shortages. The unit costs are: [ Regular production - $35 Overtime - $70 Subcontracting - $0 Note: Observe the months with backorder. Those are the months in which we must consider overtime and subcontracting. Our first option will be overtime ( $70 per unit) because it cost less than subcontracting does ( $80 per unit). Max. OT is 20 units..