A sequencing system for at least one preparation station, configured to sequence loads originating from at least one external unit, via at least one incoming forward conveyor (201, 202), and to provide said at least one preparation station, via at least one outgoing forward conveyor (401, 402), with at least one sequence comprising loads in a desired order, characterised in that it comprises: - a managed elevator with nacelles circulating in a closed loop, called a paternoster, each nacelle allowing to transport at least one load and being equipped with a load transfer device on or outside said nacelle; - at least one buffer location, configured to temporarily receive at least one load originating from the paternoster; and - a control unit, configured to organise the movements of the loads in the system and to process each load arriving at the entrance of the paternoster, via said at least one incoming forward conveyor (201, 202), according to one of the following modes, selected according to the desired place for said load in said at least one sequence: (a) after introduction into the paternoster, the load undergoes a bypass transfer between two nacelles positioned facing each other, by implementing the load transfer devices of the two nacelles, then is presented to said at least one outgoing forward conveyor (401, 402); (b) after introduction into the paternoster, the load undergoes at least one buffer transfer to a given buffer location, then is subsequently placed back in the paternoster and finally presented to said at least one outgoing forward conveyor (401, 402); (c) after introduction into the paternoster, the load is transported therein without bypass transfer or buffer transfer, then presented to said at least one outgoing forward conveyor (401, 402). - a managed elevator with nacelles circulating in a closed loop, called a paternoster, each nacelle allowing to transport at least one load and being equipped with a load transfer device on or outside said nacelle; - at least one buffer location, configured to temporarily receive at least one load originating from the paternoster; and - a control unit, configured to organise the movements of the loads in the system and to process each load arriving at the entrance of the paternoster, via said at least one incoming forward conveyor (201, 202), according to one of the following modes, selected according to the desired place for said load in said at least one sequence: (a) after introduction into the paternoster, the load undergoes a bypass transfer between two nacelles positioned facing each other, by implementing the load transfer devices of the two nacelles, then is presented to said at least one outgoing forward conveyor (401, 402); (b) after introduction into the paternoster, the load undergoes at least one buffer transfer to a given buffer location, then is subsequently placed back in the paternoster and finally presented to said at least one outgoing forward conveyor (401, 402); (c) after introduction into the paternoster, the load is transported therein without bypass transfer or buffer transfer, then presented to said at least one outgoing forward conveyor (401, 402). (a) after introduction into the paternoster, the load undergoes a bypass transfer between two nacelles positioned facing each other, by implementing the load transfer devices of the two nacelles, then is presented to said at least one outgoing forward conveyor (401, 402); (b) after introduction into the paternoster, the load undergoes at least one buffer transfer to a given buffer location, then is subsequently placed back in the paternoster and finally presented to said at least one outgoing forward conveyor (401, 402); (c) after introduction into the paternoster, the load is transported therein without bypass transfer or buffer transfer, then presented to said at least one outgoing forward conveyor (401, 402).