Chapter 5 is a detailed tutorial on using discrete-event simulation to analyze four fundamental inventory control systems for managing nonperishable inventory items. Motivated by a case study from an automotive part retailer seeking optimal inventory levels for products with varying characteristics, the chapter guides readers through building four inventory control models. Starting with the Basic Economic Order Quantity (EOQ), the model’s complexity is gradually increased to incorporate four control systems within the same simulation model: controlling the replenishment order quantity based on both fixed quantities and dynamic order-up-to policies; controlling the timing of orders both by regular replenishment intervals and by continuous review. Inventory models factor in the holding costs, ordering costs, and stockout costs. The model is used to demonstrate the effectiveness of the EOQ model and the EOQ model allowing for planned shortages. The chapter further explores experimental designs to understand how the four inventory models compare under three experiments: managing inventory with demand shocks, addressing lead time disruptions, and balancing trade-offs between inventory cost efficiency and customer responsiveness. It concludes with activities, extensions, and discussion.