A product order fulfillment system includes multiple decks arrayed at different levels and defining multilevel decks, at least one autonomous transport vehicle on each of the decks, and configured for holding and transporting a pickface on each deck, at least one lift, traversing and connecting more than one level of the decks, and arranged for lifting and lowering the pickface from the decks, and at least one pickface transfer station on each deck interfacing between the transport vehicle and the at least one lift to effect transfer of the pickface between the transport vehicle and the at least one lift, the at least one lift defines a fulfillment stream of mixed case pickfaces outbound from the multilevel decks to a load fill, at least one stream of the fulfillment stream has an ordered sequence of streaming pickfaces wherein the ordered sequence of streaming pickfaces is based on another fulfilment stream.