|The purpose of this retrospective study was to determine the appropriate inventory management method that requires minimum inventory total cost at Warinchamrab hospital, Ubonratchatani province. This descriptive study was carried out for one year from October 1st, 2006 to September 30th, 2007. The basic cost data was collected by using the method of the International Health Policy Program, Thailand (IHPP) which included labor cost, material cost, and capital cost. The Activity-Based Costing technique was applied to calculate the inventory management cost consisting of order and storage costs. The ABC analysis method was used to classify inventory drugs into categories A, B, and C based on the individual collective drug usage costs per year. Only the total costs of drugs in category A and C were determined based on the Economic Ordering Quantity (EOQ) and then compared with the total cost of the current inventory management method.
According to the study, the comparison of the total costs of categories A and C with
59 drugs each yielded that under the condition that 1 purchase order contained 1, 2 or 3 items of drugs, the inventory management total costs of the EOQ method were lower than those of the current inventory management method by 290,255.44 baht, 325,523.55 baht and 337,827.63 baht per year respectively.
This study suggests that using the EOQ method seems to be an effective way to reduce the inventory management total cost. However, should the EOQ method be put to practice, modification is needed for individual drugs since drug use rates are inconsistent through each year.