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 , and to provide said at least one preparation station, via at least one outgoing forward conveyor , 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 , 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 ; (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 ; (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 . - 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 , 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 ; (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 ; (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 . (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 ; (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 ; (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 . <EOS>