Miele is known worldwide for its premium domestic appliances for cooking, baking, steam cooking, refrigeration and freezing, coffee preparation, dishwashing, laundry and floor care. In addition, there are dishwashers, washing machines and tumble dryers for commercial use as well as cleaning, disinfection and sterilization appliances for medical facilities and laboratories. In line with the founders' motto "Always better", Miele sets high standards for the reliability and durability of its appliances. This is why the spare parts business and after-sales service are so important. Because the product range is becoming ever more extensive and the sales channels more diverse, Miele decided to reorganize its spare parts logistics and expand the old, no longer expandable ZEL in Gütersloh with a new building. The project, which was realized within sight of the main plant on a site owned by Miele, was intended to further centralize the storage of spare parts and accessories on the one hand and to simplify direct deliveries to customers and technicians on the other.
Asked to be the general contractor for the automated warehouse technology, Gebhardt Fördertechnik designed the technical implementation of the material flow systems and realized the "intralogistical inner workings" of the new warehouse within ten months. "We started installing the first racks in December 2015," recalls project manager Thomas Engelhardt. The order had previously been placed in May of that year. This includes a pallet high-bay warehouse (HRL), an automated small parts warehouse (AKL), goods-in and picking workstations, consolidation areas, consolidation racks, storage and retrieval machines (SRM), pallet conveyor technology (PFT), container conveyor technology (BFT), packing stations and a telescopic belt conveyor as a sorter.

Full operation has been running for over a year
After an intensive test phase, the new ZEL has been in full operation since October 2016: In the central incoming goods department, spare parts are mainly delivered to the new warehouse on pallets. Employees register the delivered goods in Miele's Warehouse Management System (WMS), which decides whether the goods should be stored in the manual fast-moving parts area connected to BFT, the manual pallet warehouse, the miniload or the high-bay warehouse. Small parts are repacked into containers by the employees and pushed onto the BFT. After the automatic check for overheight or overload, the 600 x 400 x 220 millimeter containers weighing up to 25 kilograms are moved into the miniload.

The pallets are placed on the loading station by the employees using forklift trucks and, after a contour and weight check, are automatically transferred to the pallet HBW via the PFT. The almost 18,700 storage locations in the HBW are spread over eight aisles and a height of almost 25 meters. Up to 5,000 different Miele items are stored here. Eight pallet stacker cranes ensure that almost 300 pallets can be stored and retrieved per hour.
The miniload warehouse has 43,400 single-deep storage locations in six aisles at a height of around 13 meters. A total of up to 25,000 different items are stored here. The six Cheetah Eco storage and retrieval machines from Gebhardt with a capacity of up to 120 double cycles per hour handle the automatic storage and retrieval of the containers.
The totes are transported to the picking workstations or to the storage tables at a speed of 0.8 meters per second via the BFT in the miniload pre-zone. AKL picking takes place at a total of six workstations according to the goods-to-person principle. The pickers remove the goods from the ergonomically positioned source containers and repack the required items into the order trays provided, which are then transferred to the central picking loop via one of a total of three lifters. This connects all stations in all hall and warehouse areas via two levels, from which spare parts for the order trays are taken.

Ergonomically optimized workstations
The order trays are then transported via the loop to consolidation or directly to packaging. Empty order trays are returned to the picking station via a separate empty container supply line above the picking loop using the lifters. In total, the system can process up to 1,200 order trays per hour. In the HBW picking area, the pallets are automatically transported to one of the six PFT picking workstations. Here, the goods are first recorded using a hand scanner and then repacked into order trays. These order trays are lifted to the central picking loop by a total of three lifts. Empty containers are fed in in the same way as in the miniload. The order pickers' workstations have been jointly developed and designed by Gebhardt and Miele according to the latest ergonomic aspects. This means that the employees in the conveyor technology area can tilt both the pallets and the order containers.

For reasons of sustainability: Reusable cartons
Another part of the new ZEL is consolidation. Here, the individual items of an order from the various storage areas are buffered in a shelving rack system in order to subsequently combine them into one shipment. For this purpose, the items are removed by the employees from the order trays delivered via the BFT and sorted into the designated compartment. In the consolidation process, several orders from a service technician can also be combined over the course of the day so that they can then be packed in a box and dispatched. For sustainability reasons, Miele uses reusable cardboard boxes to supply the service technicians, which are folded and sent back as empties or with returns. A total of 2,250 storage spaces are available in the consolidation area. The spare parts and accessories are transported from the consolidation area to the packaging workstations via the BFT lines. The finished orders are placed by the employees in order trays or technician cartons on the conveyor system.

In the redundant packaging area with two times eight workstations, up to 8,000 orders are prepared for dispatch in one day at peak times. The two S-conveyors together transport up to 1,200 order trays per hour from consolidation to the workstations. All cartons then pass through two strapping machines and a weight and volume measuring unit before being discharged via a lift table sorter to one of nine different destinations. The Gebhardt F-RED sorter bundles the two dispatch lines and can transport different carton sizes quietly and gently. Two target tours are directly connected to the Gebhardt Con-Boom telescopic belt conveyor, which can be used to transport the cardboard boxes to the truck or loading bridge. "The sorter with a capacity of up to 1,800 shipping cartons is very successful. The pallet conveyor technology with a peak throughput of 300 pallets per hour and the order picking loop with a throughput of 1,200 order trays per hour also reflect the size and performance of the system," explains Engelhardt.

The Gebhardt-Storeware visualization system ensures that Miele employees have a constant overview of the status of the entire system and individual system components. Differences between actual and target states are recorded in real time, as well as any faults. The intralogistics specialist has also installed all PLC controls and implemented the interface to the Miele material flow system. Miele has concluded a service contract with Gebhardt for the maintenance of the systems and assistance in the event of faults, including hotline support. "Always better" - the guiding principle of the long-established company is reflected not least in the improved performance of the new ZEL: the warehouse can handle around 8,000 orders per day with up to 25,000 order items at peak times and is therefore well equipped for the future. Service technicians throughout Germany receive parts ordered by 4 p.m. by 7 a.m. the following day. Dealers and private customers in Germany and some European countries are also supplied directly from Gütersloh. From here, the worldwide stock replenishment is also sent to the sales companies in 48 countries - 200 pallets a day.