FEFO is an inventory rotation method that prioritizes the shipment of items with the earliest expiry dates, regardless of when they were received. It’s especially critical in industries like food, pharmaceuticals, and cosmetics to prevent waste and ensure compliance with safety standards. 

A WMS using FEFO automatically suggests or enforces picking items closest to expiration, rather than just the oldest stock received (which FIFO would do). For example, if two batches of protein bars are in stock—one expiring in 20 days and one in 45—the system will ensure the 20-day stock is picked first, even if the other batch arrived earlier.