You must establish the Sales and Operation Planning for the company C & C during the next six months. You will assess three possible plans: I Plan 1: Producing the monthly needs by varying the number of operators. The computing of the variation of the workforce is done according to the preceding month. I Plan 2: Producing average monthly forecast demand over the six months by varying the workforce only the rst month and maintaining the constant workforce after. I Plan 3: Producing the lowest monthly forecast demand (April) by varying the effective the rst month and maintaining the constant workforce after. The company uses subcontractors for unmet needs through domestic production. Even, in case of subcontracting, the company C&C supports the storage costs and the materials costs. The sales forecast for January to June are as follows (in units): 1800, 1500, 1100, 900, 1100, and 1700. The initial stock in early January and that of June were 400 units. The company has no obligation to maintain stocks in other months. The initial workforce is 42 operators. Company policy prohibits overtime; and the calculations should be made on the basis of 8 working hours per day, 20 days a month. The following cost elements were identied in the company's accounts: I Materials cost 100 / unit I Inventory holding cost 10 / unit-month I Shortage cost................. it 50 / unitmonth I Subcontracting cost................ 100 / unit (excluding material] I Hiring and training costs 1,000 / hiring I Layoff cost ...................... 2,000 / dismissal I Working time per unit 5 hours I Labor cost ................ 15 I hour