Install the software on a PC or Mac, specify the size of the enclosure you think you'll need, then populate the DIN rails with various eDIN products. All existing eDIN products are included in the pulldown menus. The tool won't let you design something that can't be built, as it keeps track of how many inches of rail each device occupies. The finished output is a PDF with a rendering of the cabinet, and a complete BOM.

Systems which can be factory-assembled (based on the 1105, 1106, 1107 and 1108 enclosures) produce a single part number which you can use to order. The rack mount 1103 and large 1109 cannot be factory assembled, but the full Bill of Materials is produced, and rail length checks are still enforced.