In: Operations Management
A supplier offers you the following discount table for the purchase of your main product, whose annual demand you have estimated at 5,000 units. The cost of issuing a purchase order is $ 49, and it has also been estimated that the annual cost of storing a unit in inventory is 20% of the cost of purchasing the product. What is the order quantity that minimizes the total cost of inventory?
| 
 Q ( Cantidad)  | 
 Discount %  | 
 Costo Unitario  | 
| 
 0 - 999  | 
 0 %  | 
 5  | 
| 
 1 000 - 1 999  | 
 2 %  | 
|
| 
 2 000 o más  | 
 3 %  | 
Answer: 1000 units
Explanation:

Annual Demand (D) = 5000
Price per unit (P) =(1 - Discount %/100)*5
Annual Holding Cost per unit = 20% of P
Cost per order (S) = $49
EOQ = SQRT(2*S*D/H)
If EOQ > the upper limit of the range then there is no feasible solution
If EOQ < lower limit of the range then lower limit is the Feasible EOQ
Annual Ordering Cost = (D/Q)*S
Annual Holding Cost = (Q/2)*H
Annual Purchasing Cost = D*P
Total Cost = Annual Ordering Cost + Annual Holding Cost + Annual Purchasing Cost
Total cost for Q=1000 is the lowest
so, Optimal Order Quantity = 1000 units