• Russarin Jiraruttrakul Assumption University
  • Srobol Smutkupt Assumption University
  • Wasana Marksin Assumption University
  • Liang Liu Assumption University
  • Chanasit Thanathawee Assumption University


This research study applies an EOQ model (Economic Order Quantity) to reduce an inventory cost. The focus ABC Company is a Beer Importer in Thailand. It faced the problem of high inventory cost and lackluster inventory management. The root cause was that the Company had no standardized ordering process, which meant a high cost of carrying excess inventory, or having too little to meet demand. It also meant paying a high storage charge.

The EOQ Model was proposed, to make substantial improvements. Historical inventory stock data for years 2014 and 2015 shows that the ABC Company had low stock at the end of 2014, which meant the company was not able to fulfill customer demand. Conversely, it had excess stock at the end of 2015 which increased the carrying cost until the product moved from the warehouse (the internal supply chain) on to customers in the external supply chain.


The researchers collected historical data from June 2015 to May 2016 (twelve months) to compute and simulate in the EOQ model, thus identifying the re-order point and safety stock, in order to find the optimal order quantity for inventory. This enabled the identification of appropriate inventory levels and buffer stock until arrival of the next shipment. The driving objective of this research was to gain cost savings through an efficient and effective inventory management system. 

After simulation with the EOQ model, the result indicates that the ABC Company can accomplish cost savings amounting to 50% of the old annual inventory cost. Therefore, the ABC Company should implement the tested EOQ model and its re-order points, to achieve the ultimate aim of improving customer satisfaction, through buying the optimal order quantity, achieving appropriate inventory levels, and minimizing inventory cost.