Solution :
1. Ordering quantity 500 1000 10000 30000 80000
2. No. of orders 16 8 0.8 0.27 0.1
3. Average inventory 250 500 5000 15000 40000
4. Value of average 2750 5250 50000 142500 370000
inventory
5. Monthly total cost
a). Cost of material 88000 84000 80000 760000 740000
b). Ordering cost 19200 9600 960 320 120
c). Carrying cost 27.5 52.5 500 1425 3700
Total monthly cost 107227.5 93652.5 81460 77745 77820
Among the total monthly cost, $ 77,745 is the least cost.
Therefore, the optimum order size of quantity = 30,000
The number of orders per month = 8000/30000 = 0.267
Time between two consecutive orders = 30000/8000 = 3.75 months
