This study aims to find out: (1) The economical and optimal ordering of raw materials for PRIMKOPTI "Mekar Jaya" members calculated using the EOQ method is (2) The safety stock number for soybean needed by the members is (3) When the members reorder soybean raw material supplies using the EOQ method.
This study used descriptive method with quantitative approach. Sample of the study was 31 respondents taken by using random sampling technique. Data of the study were collected by using observation, interviews, and recording and analyzed by using EOQ method.
Results of the study showed: (1) the economic and optimal standard needs of the members calculated by the EOQ method was 664.32 Kg, with an order frequency of 2 times in a month and the cost incurred was IDR 15,203.88. (2) The number of safety supplies of soybean raw materials that must be available was 3.08 Kg. (3) The members should re-order soybean raw materials at the time of supply of 46.41 Kg.