Methods and systems for allocating cells of a sorting apparatus include associating, in a database, an identifier of the sorting apparatus with an identifier of a first container storing a first item of the purchase order, the purchase order including a second item stored in a second container; before associating the sorting apparatus with the second container, receiving an identifier of the first item; determining, in the database using the identifier of the first item, whether any cell of the sorting apparatus is associated with the purchase order; when no cell of the sorting apparatus is associated with the purchase order, associating, in the database, an identifier of a cell of the sorting apparatus with the identifier of the purchase order; and transmitting a first signal to a computer associated with a worker instructing placement of the first item in the cell.