The invention relates to a control apparatus for controlling system including image forming apparatus and sheet discharge apparatus. The control apparatus includes a processor and a memory to controla system having an image forming apparatus and a sheet discharge apparatus. Executing a memory stored program causes the control apparatus to receive configuration information of the system and generate a system configuration image, receive stacking state information and generate a sheet bundle image, display a screen, receive job identification information of an image forming job of sheets to bepicked up, and display a thumbnail image. The stacking state information includes a stacking amount of sheets stacked on a sheet stacking tray. The sheet bundle image represents the sheets stacked ona sheet stacking tray based on the stacking state information. The system configuration image and the sheet bundle image are combined in the screen. The thumbnail image is based on the job identification information.