Reduce Holding Costs
Inventory holding costs can cut into your ROI. You can reduce holding costs by improving space utilization. That might mean you need to change the layout of your warehouse to get more space. For instance, you can reduce the space between aisles. Then, you can get narrow aisle reach trucks so you can still access the inventory.
You should also remove products that you do not need from your warehouse. Warehouses often become storage units for companies, and that should never be the case. If you do not plan on selling the item, get rid of it. Then, fill that empty space with something that you will sell quickly.