Zero Lead Time is an ideal scenario in supply chain management where replenishment or production occurs instantaneously upon demand. While practically impossible, it represents the goal of minimizing delays to achieve perfect synchronization between supply and demand. Reducing lead times enhances inventory optimization by lowering the need for safety stock, increasing responsiveness, and reducing the risk of stockouts or overstock. Technologies like real-time data analytics, automation, and agile manufacturing support progress toward this ideal. Supply chains with near-zero lead times can better handle demand variability and improve service levels, but they require robust infrastructure and close supplier collaboration.