PT XYZ is a packaged beverage manufacturer striving to increase its market share by regularly launching new products. In practice, not all new products are well-received by the market, resulting in significant differences between sales targets and actual sales. Failure to achieve sales targets leads to the accumulation of raw materials and high scrap of raw materials, thus disrupting the company’s cash flow and harming the environment. Currently, the average inventory level of raw materials for new launched products is 196 days, with an estimated raw material scrap rate of 25%. In comparison, the company’s target maximum inventory level is 30 days and has a 0% scrap rate of inventory. This study employs a mixed-methods approach to develop a new inventory replenishment system and implement the Internet of Things (IoT). The methodology includes a detailed analysis of current inventory practices, IoT integration for real-time monitoring, and the application of advanced inventory management techniques to achieve sustainable manufacturing (SDG 9). Between January and April 2024, the new inventory model and IoT implementation reduced stock levels by 86.2%, reduced days of inventory from 196 to 27 days, and eliminated the waste of raw material (SDG 12) by achieving a 0% scrap rate.