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 $70 per unit. Inventory holding cost is $25 per unit per month. Ignore any idle-time costs. Evaluate the following plans D and E. Plan D: Keep the current workforce stable at producing 1,600 units per month. In addition to the regular production, another 20% of the normal production units can be produced in overtime at an additional cost of $55 per unit. A warehouse now constrains the maximum allowable inventory on hand to 600 units or less. Note: Do not produce in overtime if production or inventory are adequate to cover demand