摘要:Abstract Despite the importance and potential for companies to minimize costs by reducing the safety stock levels using the modular product system, this has not been extensively studied; its study has been limited by the inherent complexity of the production system. The modular product system arises to try meeting the increasing demand of customized products, which are products manufactured with virtually the same costs, lead times and high quality of products made with mass production. This paper develops a new method to calculate and to reduce the safety stock levels for modular product system under the Make to Order strategy, where, besides considering its reduction using commonality in modules and components, it also considers a substitutability factor devised from Group Technology theory. The results show that with the application of the proposed model in a basic example, the safety stock levels in modular product system has been reduced.