A method for treating and/or handling piece goods (14, 14a, 14b, 14c, 14d, 14e, 14f) being moved in at least one row, in particular, for the purpose of forming layers, which piece goods (14, 14a, 14b, 14c, 14d, 14e, 14f) of a row each have approximately equal or different and/or variable spaces between each other, and which piece goods (14, 14a, 14b, 14c, 14d, 14e, 14f) are fed by means of at least one horizontal conveyor from a packaging station and/or equipping station or from another upstream handling device and/or conveying device to a grouping station and/or layer-forming station having a seizing range, which seizing range defines and/or spatially delimits a movement range of at least one manipulator, which at least one manipulator seizes at least one piece good (14, 14a, 14b, 14c, 14d, 14e, 14f) in a work cycle in a gripping manner from the at least one row and moves it into a defined relative target position and/or target alignment, in particular, with regard to a piece good layer to be formed, - wherein the at least one horizontal conveyor arranged upstream in transport direction of the piece goods (14, 14a, 14b, 14c, 14d, 14e, 14f) from the grouping station and/or layer-forming station is assigned at least one sensor device for the acquisition of position data and/or dimension data and/or alignment data regarding the piece goods (14, 14a, 14b, 14c, 14d, 14e, 14f) being transported on the horizontal conveyor, - wherein the sensor device generates electronic output signals from the acquired position data and/or dimension data and/or alignment data for the piece goods (14, 14a, 14b, 14c, 14d, 14e, 14f) being transported on the horizontal conveyor, - which output signals are processed and used to control the manipulator in a manner adapted to the detected positions and/or dimensions and/or alignments of piece goods, in particular, with regard to a particular piece good layer to be formed by means of the manipulator, - wherein the manipulator moves and/or rotates and/or shifts individual or a plurality of piece goods (14, 14a, 14b, 14c, 14d, 14e, 14f) within the seizing range based on the sensor signals acquired and processed by the sensor device and provided to a control device of the manipulator, - wherein the sensor device performs a mechanical scan, characterised in that - the sensor device performs the mechanical scan with adjustable lateral guide rails on both sides of a transport path of the piece goods on the horizontal conveyor, wherein a width of a piece good is determined by means of a detection of torques of actuators during the advancing of the adjustable lateral guide rails toward side surfaces of the piece goods. - wherein the at least one horizontal conveyor arranged upstream in transport direction of the piece goods (14, 14a, 14b, 14c, 14d, 14e, 14f) from the grouping station and/or layer-forming station is assigned at least one sensor device for the acquisition of position data and/or dimension data and/or alignment data regarding the piece goods (14, 14a, 14b, 14c, 14d, 14e, 14f) being transported on the horizontal conveyor, - wherein the sensor device generates electronic output signals from the acquired position data and/or dimension data and/or alignment data for the piece goods (14, 14a, 14b, 14c, 14d, 14e, 14f) being transported on the horizontal conveyor, - which output signals are processed and used to control the manipulator in a manner adapted to the detected positions and/or dimensions and/or alignments of piece goods, in particular, with regard to a particular piece good layer to be formed by means of the manipulator, - wherein the manipulator moves and/or rotates and/or shifts individual or a plurality of piece goods (14, 14a, 14b, 14c, 14d, 14e, 14f) within the seizing range based on the sensor signals acquired and processed by the sensor device and provided to a control device of the manipulator, - wherein the sensor device performs a mechanical scan, characterised in that - the sensor device performs the mechanical scan with adjustable lateral guide rails on both sides of a transport path of the piece goods on the horizontal conveyor, wherein a width of a piece good is determined by means of a detection of torques of actuators during the advancing of the adjustable lateral guide rails toward side surfaces of the piece goods.