Consider a four-month sales and operations planning problem with the monthly demand data shown below. For questions 1, 2 and 3: (i) each employee makes 5 units per month, (ii) each plan should start and end with 10 employees, (iii) each plan should start with 20 units of inventory (at the end of April=beginning of May), (iv) each employee hired costs $400 and each employee laid off (fired) costs $600, (v) the inventory holding cost is $100 for each unit each month, and (vi) the production cost is $200 per unit and the selling price is $350 per unit.

1. Fill in the shaded cells in the table below to show the level plan that ends with 20 units of inventory (at the end of August as shown). Negative inventory is viewed as backorders and costs $200 per unit each month. What is the total profit for this level plan?

Month	Demand (units)	Employees	Production	Hiring	Firing	Inventory
May	90
June	90
July	50
August	70					20
hiring/firing at end of August						--

Total Profit = __________

2. Consider now a different level plan (produce the same each month) that starts with 20 units of inventory at the beginning of May and ends with 60 (not 20) units of inventory at the end of August. How many employees are needed each month (the same number each month) for this level plan?

Number of Employees needed each month = __________

3. Consider a plan that starts with 20 units of inventory at the beginning of May, has zero inventory at the end of May-July (as shown below), and has 20 units at the end of August? Fill in the shaded cells in the table below and calculate the total profit.

Month	Demand (units)	Employees	Production	Hiring	Firing	Inventory
May	90					0
June	90					0
July	50					0
August	70					20
hiring/firing at end of August						--

Total Profit = __________