Once the locations are created, they need to be assigned to the items. Every item should have a list of locations where it can be found in the warehouse.
Location assignment for items is set on the Item layout, in the More... button.
When an item only has a picking location, it is marked as both Putaway and Picking. For example, the Durango warehouse has items stored at location 1516. This is where items are putaway and picked. Therefore, the Durango warehouse does not have a replenishment option for this item.
However, the Sylvania warehouse has two distinct locations for putaway and picking. The putaway location is also marked as the replensihment source.