A computer manufacturer is developing a production schedule for the next four quarters. Demand for this manufacturer's laptop is estimated to be 1200 units in Q1; 2100 in Q2; 1500 in 3 quarters; and 600 in Q4. Up to 1400 laptops can be produced in regular time labor at a cost of $1,200 per unit each quarter. An unlimited number of laptops can be produced overtime each quarter at a cost of $1800 per unit. 2% of all units produced are defective and cannot be used to meet demand. After each quarter's demand is met and defective items are calculated, a holding cost of $300 per computer is assessed. All demands must be met on time, and units produced in one quarter can be used to meet demand for the current quarter as well as future quarters. Suppose there were no computers in inventory at the beginning of Q1. Using the shell provided in the GS 2.xlsx file, formulate and solve a linear programming model to find the production schedule that minimizes the total cost over the given planning horizon.

Problem 3
Unit production cost with normal time labor	$1,200
Unit production cost with overtime	$1,800
unit holding cost	$ 300
Normal time production capacity every three months	1400
Proportion of defectively produced units	%2
Initial inventory	0
	Quarter 1	quarter 2	quarter 3	quarter 4
Inventory level before quarter production
Normal time production level for the quarter
Normal time production capacity
Overtime production level for the quarter
Total number of units produced during the quarter
Number of defective units produced
Number available to meet quarterly demand
Quarterly demand	1200	2100	1500	600
Ending inventory
	Quarter 1	quarter 2	quarter 3	quarter 4
Quarterly production costs with regular time labor
Quarterly production costs with overtime
Quarterly holding costs
Total quarterly costs
Total cost for the planning horizon