A combine harvester with a driver assistance system, the combine harvester comprising a display with an input-output device, a plurality of working mechanisms including a threshing system and a cleaning system, a plurality of sensors (140, 144, 148, 152, 154, 156, 158, 162, 166, 168) arranged to monitor the working mechanisms, a plurality of actuators (146, 150, 160, 170, 172) provided to control the working mechanisms and an arithmetic logic unit coupled to the actuators (146, 150, 160, 170, 172), the plurality of sensors (140, 144, 148, 152, 154, 156, 158, 162, 166, 168) and the display, wherein the arithmetic logic unit is configured to retrieve digital instructions and digital data stored in an electronic memory circuit, to save digital data to the electronic memory circuit, to display screens of information on the display, and to retrieve operator commands from the display, the digital instructions including instructions to the arithmetic logic unit to perform the following: display a first screen on the display, the first screen showing regions (602, 604, 606) representing general areas of improvement of crop processing in the combine harvester, the general areas of improvement including grain quality, grain loss and straw condition, permit an operator to select one of the regions (602, 604, 606), display a second screen if the operator has selected the region indicative of grain quality as general area of improvement, the second screen showing regions (802, 804, 806, 808, 810) assigned to individual areas of improvement of crop processing in the combine harvester including broken grain, chaff/husks, straw pieces/cobs, unthreshed material and excess tailings, permit the operator to select any number of said individual areas from said second screen by selecting the corresponding selectable screen region (802, 804, 806, 808, 810), display a third screen if the operator has selected the region indicative of grain loss as general area of improvement of crop processing in the combine harvester, the third screen showing regions (902, 904, 906) assigned to individual areas of improvement including separator loss, shoe loss and unthreshed loss, permit the operator to select any number of said individual areas from said third screen by selecting the corresponding selectable screen region (902, 904, 906) and determine at least one control adjustment to be made to a working mechanism, including referring to an internal knowledge base or expert system to determine several control adjustments that the arithmetic logic unit can take to improve more or all of the areas of improvement identified by the operator and weighting some of the possible control adjustments more than other possible control adjustments based upon whether a particular control adjustments beneficially improve more or all of the areas of improvement identified by the operator, creating a prioritized list of control adjustments. display a first screen on the display, the first screen showing regions (602, 604, 606) representing general areas of improvement of crop processing in the combine harvester, the general areas of improvement including grain quality, grain loss and straw condition, permit an operator to select one of the regions (602, 604, 606), display a second screen if the operator has selected the region indicative of grain quality as general area of improvement, the second screen showing regions (802, 804, 806, 808, 810) assigned to individual areas of improvement of crop processing in the combine harvester including broken grain, chaff/husks, straw pieces/cobs, unthreshed material and excess tailings, permit the operator to select any number of said individual areas from said second screen by selecting the corresponding selectable screen region (802, 804, 806, 808, 810), display a third screen if the operator has selected the region indicative of grain loss as general area of improvement of crop processing in the combine harvester, the third screen showing regions (902, 904, 906) assigned to individual areas of improvement including separator loss, shoe loss and unthreshed loss, permit the operator to select any number of said individual areas from said third screen by selecting the corresponding selectable screen region (902, 904, 906) and determine at least one control adjustment to be made to a working mechanism, including referring to an internal knowledge base or expert system to determine several control adjustments that the arithmetic logic unit can take to improve more or all of the areas of improvement identified by the operator and weighting some of the possible control adjustments more than other possible control adjustments based upon whether a particular control adjustments beneficially improve more or all of the areas of improvement identified by the operator, creating a prioritized list of control adjustments.