the storage zone is the area where the packages are stored. It is some-times divided into a remote reserve zone (RZ), where the large load units coming from the receiving zone are stored, and a small-sized rapid access storage zone (pick zone (PZ)), from which the packages are retrieved for the formation of outgoing load units. This solution gives the possibility of keeping at a low level the workload (transfer time) of the staff involved in material-handling operations, but it requires the periodic replenishment of the PZ with the packages stored in the RZ;