Abstract: In a data processing apparatus, a processor of an S88 processing unit comprises: a display unit that displays a diagram including a plurality of figures representing a processing unit and a connecting line representing a processing flow by connecting the plurality of figures together; an editing unit that executes, when receiving an editing command to edit the diagram from a user via a screen displayed by the display unit, the editing thus requested; and a link control unit that determines, when the editing unit receives an editing command to connect a first figure representing start or end of branched processing with a second figure representing a processing unit by using a connecting line, a point on a line forming the second figure, to which the connecting line is to be connected, such that one end of the connecting line is automatically connected, and that also connects, when receiving from the user a specification that specifies any position on a line to which the connecting line is to be connected among