Systems and methods for automatic reorganization of pick slot assignments in a warehouse are described. Replenishments of products from storage slots to pick slots are used to perform product relocation to new pick slots for active items, along with traditional relocation moves for inactive items to establish open pick slots. By use of replenishments, the blocking of product relocations to new pick slots due to order picking activity is reduced or eliminated, enabling product relocation for improved slotting to be performed during normal warehouse operations. A dynamic slotting method is described where each item is assigned to a zone having a designated set of slots and each item is replenished to any new slot, as compared to an originally assigned slot, in the zone as stock is depleted by picking. Inactive items may be proactively relocated to temporary slots to reduce or eliminate the blocking of relocations of active items.