The purpose of this research is to find the Economic Order Quantity (EOQ), Safety Stock (SS) and Re Order Point (ROP) of printing inks in a corrugated paper production case study company. Currently printing inks inventory is controlled by the employee’s experience that causes high inventory stock level and high cost of inventory control. The research methodology has following three steps; (1) Using the ABC classification concept to classify the printing inks. The result shows that 25 of 135 types are classified as group A. (2) Using Variability Coefficient (VC) value to validate the demand data before using the EOQ model. The result shows that there are 23 types of printing inks be able to use EOQ model. (3) Calculation of EOQ, SS and ROP for each printing ink. The result of using the proposed method instead of employee’s experience shows that inventory stock level is reduced from 4,191 kg to 2751 kg. The inventory capital expenditure also is reduced from 473,583 to 310,863 baht a year, a decrease of 162,720 baht a year or 34.4% reduction.
Keywords
Economic Order Quantity, Safety Stock, Re Order Point