By choosing the function automatic design group selection, the selection takes place according to the predefined configurations for all catenary elements which were selected in the graphic before. For every selected catenary element and for every selection table defined in the configuration (node selection) the selection tree is run through. In the branches of the selection tree, the rule given in the specific grid by using the variable for the current catenary element is evaluated and branched out in the respective sub tree. The assembly at the leave of the selection tree is then added to the current catenary element.