Research Optimization Of High-mixed Low-volume Purchase Order Of Roplan Group

This paper focuses on the Roplan Group’s optimization of its purchase order model through the combination of vendor managed inventory and economic order quantity,to achieve lower cost and shorter lead time.The Roplan Group is a Swedish company which specializes in the designing and production of customize design mechanical seals.The order pattern is a typical customized high-mixed,lowvolume model.The current purchase order model is to purchase batch-by-batch according to the quantity of customer orders.The high-mixed,low-volume model leads to high cost and low bargaining power on suppliers.In the yearly summary of 2017,Roplan group found that the purchase cost saving can be achieved by integrating the order quantity and batch,and it is concluded that the daily purchase order can be optimized through the combination of annual order and economic order quantity.This paper analyzed two problems: the independent purchasing in each branch companies within the group and repeat orders.It determined the target products by ABC classification,applied the VMI theory and EOQ theory to the purchase order optimization,established an annual order judgment model and EOQ calculation model,and formulated a purchase order optimization operation model combining annual order and EOQ to achieve the expected reduction in cost and shortened lead time.Taking the Roplan Sales(Ningbo)Co.,Ltd.as an example,after applying the operation in July of 2018,the gross margin increased from 16.25% to 21.92%;the number of arrival batches decreased from 6935 batches to 5698 batches in 2018,meanwhile the lead time of annual order parts was reduced from 40 working days to 5 working days due to sufficient stock at suppliers.The OTD rate increased from 90.5% in the first half of 2018 to 94.5% in the second half of the year;the average supplier rejection rate dropped from 2.16% in the first half of 2018 to1.17% in the second half of the year.