A reduction in purchased lot sizes means ordering smaller quantities of materials more frequently. This reduces the average inventory level and the carrying cost of inventory. However, it also increases the frequency of orders and the ordering cost. The reorder point (ROP) is the level of inventory that triggers a new order, and it depends on the demand rate, the lead time, and the safety stock. The ROP is not affected by the lot size, unless the demand or the lead time changes. The setup time is the time required to prepare a machine or a process for production, and it is not related to the purchased lot size. References: EXAM CONTENT MANUAL PREVIEW, page 14, section 6.1.2. Manufacturing Planning and Control for Supply Chain Management: The CPIM Reference, Second Edition, page 433, section 12.4.