- 6. Consider a twelve-month sales and operations planning problem with the monthly demand data shown in the table below. The inventory holding cost is $30 for each unit held at the end of a month. - Each employee makes 8 units per month. Each hire costs $800 and each layoff (firing) costs $200. - The plan must start and end with 10 employees. - The plan must start with 30 units of inventory (at the beginning of August). - The plan must end with at least 30 units of inventory at the end of July. - Backordering (negative inventory) is not allowed. Find the lowest cost S&OP plan where all hiring and firing must be in integers (no fractions). Report the total cost of your plan, and fill in the table below to show the number of employees hired and fired at the beginning of each month, the production and the inventory at the end of each month. a) Total cost for the plan b) Fill in the table: Month # Hired # Fired Production Inventory (30) August September October November December January February March April May June July Demand (units) 50 70 102 88 114 110 72 48 60 60 58 56