An automated storage and retrieval system including at least one autonomous transport vehicle, a transfer deck that defines a transport surface for the vehicle, at least one reciprocating lift, a first and second pickface interface station connected to the deck and spaced apart from each other, each station forming a pickface transfer interfacing between the vehicle on the deck and the lift at each station so that a pickface is transferred between the lift and the vehicle at each station, wherein the vehicle is configured to pick a first pickface at the first station, traverse the deck and buffer the first pickface, or at least a portion thereof, at the second station so that the second station has multiple pickfaces buffered on a common support in an order sequence of pickfaces according to a predetermined case out order sequence of mixed case pickfaces.