การจัดการสินค้าคงคลังของบริษัท วีพีเอฟกรุ๊ป (1973) จำกัด สาขาแม่ทา จังหวัดลำพูน

Abstract

This independent study focuses on inventory management of VPF Group (1973) Company Limited, Mae Tha Branch, Lamphun Province. The purpose of this study is to figure out how to manage the inventory of VPF Group (1973) Co., Ltd., Mae Tha branch, Lamphun Province in order to prepare sufficient inventory at minimum inventory cost. The researcher applied inventory management theory called ABC Analysis to divide inventory into three categories in descending value. In this study, the researcher focused only on Group A inventory which contains 54 items by using demand forecasting techniques including Moving Average, Exponential Smoothing, Double Exponential Smoothing, and Holt-Winter technique to analyze the data before the adjustment. After gathering all data, the researcher analyzed the coefficient of variation of demand (VC) by using the economic order quantity (EOQ) for constant demand, together with determining the order quantities to meet the requirement of operations at minimum cost (Silver Meal) for unstable demand. Then, the researcher compared the data analyzing by the coefficient of variation of demand (VC) with the data analyzing by maximum-minimum volume control technique (Max-Min) to find the best method that can reduce inventory cost. Moreover, the researcher applied ECRS principle for improving further administrative process Before the adjustment, the data showed that the inventory cost of Group A products was approximately 13.73 million THB per year. After analyzing the coefficient of variation of demand (VC) using the economic order quantity (EOQ) along with determining the order quantities to meet the requirement of operations at minimum cost (Silver Meal), the result suggested that it was possible to reduce inventory cost to 8.31 million THB per year (reduced by 5.41 million THB per year). In addition, the data analyzed by maximum-minimum volume control technique (Max-Min) showed that the total cost of inventory management reduced to 10.51 million THB per year with greater inventory than forecasted demand by 1.65 million THB. So, this cost could be transferred to other VPF Group warehouses. Therefore, the total inventory cost by analyzing maximum-minimum volume control technique (Max-Min) was approximately 8.86 million THB per year (reduced by 4.87 million THB per year). As a result, the researcher recommended the method of the coefficient of variation of demand (VC) by applying the economic order quantity (EOQ) for constant demand and determining the order quantities to meet the requirement of operations at minimum cost (Silver Meal) for unstable demand. Apart from this study, after applying ECRS principle to improve administrative process, the result suggested that the duration of goods receiving process decreases from 96 minutes to 50 minutes (decreased by 46 minutes). Also, the duration of goods distribution process decreased from 111 minutes to 40 minutes (decreased by 71 minutes). Lastly, the duration of goods ordering process decreased from 102 minutes to 31 minutes (decreased by 71 minutes). In summary, it helped reduce 188 minutes of working hours per day. Consequently, the company had more time to develop other processes instead of spending it on inventory management. In conclusion, the researcher proposed that VPF Group should apply these three steps of inventory management for further development among affiliated companies.