The hall at the ICE plant in Munich is 455 meters long and 50 meters wide and has six continuous hall tracks, each of which can accommodate a complete ICE train (Fig. 1). It is primarily ICE 3 and ICE T trains that are inspected, cleaned, maintained and repaired here. A team of 390 craftsmen work simultaneously on four levels. On the upper level, the roof level, work is carried out on pantographs, air conditioning and antennas, among other things. On the platform level below, work is carried out on exterior walls, doors and windows, maintenance of vehicle electronics and lighting, and the dining car is refilled. The third level at rail level is the main work level. This is where wheels, bogies and braking equipment, as well as transformers and oil circuits for driving heads, are checked and repaired if necessary. Finally, in the track pit, the team focuses on the underfloor area, replacing brake linings and checking the floor plates. "Perfectly coordinated work preparation, material planning and logistics are required to ensure that the downtime is only as short as necessary," explains Stefan Lorenz, Head of Materials Management.

Train sends error messages to the ICE plant in advance
In order to have the required spare parts on site as soon as the train arrives, ICE drivers traveling in southern Germany send the stored fault and error messages to Munich in advance at the touch of a button. All available spare parts as well as their drawings and circuit diagrams are stored in the IT system on call. Around 12,000 different spare parts and materials are stored in Munich in pallet and shelving racks with up to seven levels. Until the end of 2016, inventory management was still analog: Warehouse staff had entered incoming and outgoing goods manually and thus controlled the stock levels. The ICE plant then switched to digital warehouse and inventory management - in three construction phases so as not to interrupt ongoing operations, as 30 ICEs are serviced here every day. "We expect the reorganization of our warehouses to result in shorter maintenance times, as access times to spare parts and materials will be shorter thanks to clearer organization and clearly legible labeling, and barcodes will minimize error rates," explains Lorenz. "The barcodes also create the basis for the subsequent use of handhelds."

Barcode labels for around 17,000 storage locations
For the complete re-labeling of the warehouse, the newly implemented software was first used to generate a numbering plan with up to ten-digit coordinates for each individual storage location - consisting of shelf, column, level and space. Based on these specifications, ONK, the Cologne-based specialist for visual warehouse organization, produced more than 17,000 self-adhesive storage location labels, 170 aisle signs and 56 floor markings with barcoded and partially plain text representation of the respective storage location coordinates (Fig. 2 + 3).

Fig. 2 (Image: ICE maintenance workshop in Munich)

The basic structure in the shelving and pallet racking warehouses is defined by aisle signs made of rigid PVC foam measuring between 15 x 15 and 50 x 50 cm, which identify the individual rows of shelves by number. The ONK team has marked the up to seven rack levels with different background colors, e.g. yellow for level 03, light green for 05 and light blue for 07. Each of the more than 17,000 rack locations is also provided with a self-adhesive, two-line printed plastic label, which shows the location as a barcode and in plain text and contains directional arrows for upper and lower height positions. In high-traffic areas, the shelf labels are also covered with a protective laminate. For hard-to-reach shelf levels, colored multiple labels show several levels on a single label in an easily accessible location. The multiple labels contain three adjacent barcodes on a different colored background for different storage levels, which are rotated to enable error-free scanning. Finally, ONK has marked pallet storage locations with self-adhesive floor markings made of rigid PVC film, on which the storage location coordinate is shown as a barcode and in plain text.