supplying a paperboard sheet along a feed line; and

moving a slitter/scorer including at least one of a slitter and a scorer in at least one of a vertical direction by a mechanism for vertically moving said slitter/scorer and a widthwise direction by a mechanism for horizontally moving said slitter/scorer to an operative level where a surface of the paperboard sheet is processed thereby,

wherein each of said mechanism for vertically moving said slitter/scorer and said mechanism for horizontally moving said slitter scorer includes a servo motor,

and when said slitter/scorer moves from a first widthwise position of a first operative position to a second widthwise position of a second operative position, said slitter/scorer is caused to start moving only in the vertical direction while a level of said at least one of said slitter/scorer is between a bottom surface of the paperboard sheet and a top surface of the paperboard sheet, and then said slitter/scorer is moved simultaneously in the vertical direction and in a cross machine direction which said cross machine direction is oriented from said first widthwise position to said second widthwise position in part along a first diagonal path portion disposed on a first line and thereafter said slitter/scorer moves in part along a second diagonal path portion disposed on a second line that intersects the first line so that said slitter/scorer moves diagonally toward said second cross machine position before said slitter/scorer again moves only in the vertical direction and after said slitter/scorer initially moved only in the vertical direction.