The switch gears are installed into the switch cabinets according to a previously determined part list. When devices are wired, it is essential that the physical position of the devices in the switch cabinet be given and agreed on. This determines the length of cables leading to and leaving the device. In case of a modification affecting the devices, this necessary and essential information is not at hand, because, as the device is missing, the length of cables waiting to be wired into the device cannot be determined.

By means of internal development, devices missing in the switch gear are produced with a 3D printer. A device model manufactured like this and equipped with connectors substitutes for the original device and fills its physical place in the switch gear. In this way, cables leading to and leaving the device can be safely connected to the model and cable lengths can be precisely determined.