Ikea
Cost per touch inventory tactic : Ikea uses this technique where customers select and retrieve the packages themselves. The more an item moves, the more it costs. By making the customers retrieve the packages they are reducing moving and retrieval costs for an item.
High-Flow & Low-Flow Warehouse : Products stored in High flow warehouses are in high demand and they are fully automated to reduce costs per touch. Low flow warehouses are not in demand and the processes are mostly manual because the workers don’t have much to move and stock.
Walmart
Cross docking is Walmart’s strategy of replenishing inventory effectively. Cross-docking is the process of unloading materials from an inbound truck and loading these materials directly into outbound trucks with little or no storage in between.
Amazon
Products in amazons warehouse are not organized by category. They are placed on shelves as if by random. When a product is picked up hand by a collector he scans it with a handheld device to ensure that the right product is picked up. The products progress in the warehouse is monitored in every step because of the scanning of the product in each step. By doing so, Amazon is able to track where a particular product is at any given point of time.
A 90-second video on how Amazon manages its warehouse https://www.youtube.com/watch?v=5TL80_8ACPc