Optimization of Soybean Raw Material Inventory in the Tofu Agroindustry Using the EOQ Formula in Mataram City

Abstract

This study aims to: (1) Determine how to analyze the optimization of raw material inventory in the tofu agroindustry in Mataram City; (2) Determine the impact on sustainability in optimizing raw material inventory in the tofu agroindustry in Mataram City. The method used in this study is descriptive. The unit of analysis in this study is tofu entrepreneurs in Mataram City. This study was conducted in Mataram City, with 13 sub-districts; 2 were selected: Sekarbela Sub-district in Kekalik Jaya Village and Sandubaya Sub-district in Abiantubuh Baru Village, using quota sampling. Determination of sample areas using proportional random sampling, namely, 15 people. The number of samples was allocated to sub-districts using proportional random sampling, with Kekalik Jaya Village receiving 6 and Abiantubuh Baru Village receiving 8. The data used in this study are quantitative and qualitative. Data sources used include primary data and secondary data. Data collection was conducted through direct interviews with respondents. The results of this study are: (1) the analysis of soybean raw material inventory optimization in the tofu agroindustry in Mataram City is still not optimal based on the EOQ method analysis, the optimal order quantity is 34,403 kg per order, with a frequency of 20 times per year or around 1-2 times per month. This is much more efficient than the actual practice of 6,259 kg per order with a frequency of 109 times per year. The required safety stock is 7,114 kg to account for demand fluctuations and delivery delays during the 10-day lead time. The reorder point is 26,000 kg, with a total annual inventory cost of IDR 3,247,757, consisting of an ordering cost of IDR 1,623,867 and a storage cost of IDR 1,623,890. (2) The application of inventory optimization with the EOQ method has a significant positive impact on the sustainability of the tofu agroindustry in Mataram City. There was a very significant inventory cost saving of IDR 5,973,140, or 64.78% of the total actual inventory cost of IDR 9,220,897, mainly from a 81.81% reduction in ordering costs through reduced order frequency.