Research about the implementation of the Economic Order Quantity (EOQ) model is mostly done only for implementation in Make-To-Stock (MTS) companies. There has not been much recent research about the implementation of the EOQ model to companies that use make-to-order (MTO) business production strategy. Therefore, by considering the research gap as well as the need of MTO businesses to reduce their costs, the implementation of the EOQ model is applied to PT X, which is an MTO company that produces steel wheel disc. The aim of this research is to discover a better order quantity planning method by comparing the holding cost between PT X’s production system before and after the implementation of the EOQ model. The results of analysis, calculation, and validation of order quantity planning using the EOQ model showed that the implementation of the EOQ model for order quantity planning in PT X can reduce the number of losses caused by holding costs. The research is conducted assuming the supplier is a make-to-stock producer that is capable of meeting production demand with at most 1 week lead time.