If an agricultural machine breaks down suddenly and, in the worst case, during the harvest season, this can have costly consequences for the farmer. In order to minimize the duration of such breakdowns, Claas requires the constant availability of around 200,000 spare parts and their rapid delivery. Claas has invested around 22 million euros in the expansion of its central spare parts warehouse in Hamm-Uentrop to ensure that its storage capacity can cope with the increasing number of orders and spare parts in the future. The investment has resulted in a total of 58,000 pallet spaces and goods-to-person picking, which are integrated into the logistics processes of the spare parts center. Together with Claas, Unitechnik developed a scalable solution with high system performance.

The challenge of spare parts logistics
One challenge in agricultural machinery spare parts logistics is the high diversity and variance of parts: many machines are manufactured in small quantities to customer specifications. Electronic components are increasingly being installed, as well as large and bulky finished products. In order to cope with the increasing order volume in the future, a significant expansion of the plant is already planned in the concept. "Automation in spare parts logistics is the supreme discipline. In contrast to production logistics, peak times can only be planned to a limited extent, as they are beyond the control of the system operator," says Yusuf Kaya, Key Account Manager at Unitechnik Systems. The high performance requirements are met by an efficient material flow: both the storage and retrieval machines and the electric overhead conveyor vehicles are equipped with two load handling devices.

A high-bay warehouse in silo design was built on an area of 6,000 m². Of the nine aisles, the two outer ones are double-deep. All nine storage and retrieval machines are equipped with two load handling devices. They each pick up a pallet or pallet cage from the 30-metre-high rack and transfer them in pairs to the conveyor system. The pallet conveyor system in front of the high-bay warehouse is arranged in such a way that two storage and two retrieval stations are positioned next to each other. For example, the retrieval lanes for aisles 2 and 3 are next to each other. This allows the overhead monorail system to pick up two load carriers at a time.

EMS instead of conventional continuous conveyor technology
The electric monorail system (EMS) is the logistical backbone of the system. It connects the high-bay warehouse with the picking stations, the goods receiving area and the full-pallet retrieval area. It plays the most important role in the material flow with regard to the rapid storage and retrieval of pallets: In one second, the EMS vehicles cover a distance of 1.5 meters and thus travel around five times as fast as the pallet on a continuous conveyor system. In the current expansion stage, a throughput of up to 400 vehicles per hour is achieved; with a load of two pallets per vehicle, this corresponds to a peak performance of 800 pallets per hour. This is four times as much as a round trip with conventional conveyor technology. The high throughput capacity is particularly in demand during peak periods in the harvest season. With the EMS, Claas benefits from a solution that can be expanded and scaled up as required by adding further vehicles.

Yusuf Kaya explains how the EMS is integrated into the material flow: "The electric monorail system picks the pallets from the retrieval points of the high-bay warehouse and moves them to the picking Us. There it transfers two pallets at a time to the continuous conveyor system. From here, the pallets are transported to the picking stations. The return pallets are transported to the high-bay warehouse by the empty EMS vehicle. These steps are fully automated." Unitechnik designed the picking area according to the goods-to-person principle. Depending on the order volume, the parts are either immediately packed into the target container or pre-consolidated.

Ergonomic picking stations thanks to VR
In order to make the picking process as ergonomic and efficient as possible, workstation and conveyor technology alternatives were simulated in advance and discussed with the customer. "When designing workstations, we relied on virtual reality," reports Yusuf Kaya. "With the help of the virtual preview through VR glasses, we were able to realistically display and optimize the workstations." The result is a space-saving and convenient solution.

Software for efficient material flow
Whether the physical possibilities are actually used is decided by the brain of the system - the software. This is where the UniWare warehouse management software from Unitechnik comes into play. In this project, UniWare has combined the function of an extended material flow control system (MFS) with integrated system visualization. In addition to the intelligent routing of the load carriers, the storage locations in the high-bay warehouse are also managed and regularly optimized by UniWare. The operator always has an overview via the freely zoomable visualization: from the complete system overview to the switching status of an individual sensor. UniWare can be operated from the control station or via tablets and smartphones.

Equipped for today and tomorrow
"We are very satisfied with Unitechnik's performance," summarizes Dietmar Düsing, Head of Logistics and Member of the Management Board of Claas Service and Parts GmbH. "The work was carried out parallel to ongoing operations throughout the entire project. We stayed on schedule and within budget, which is not a matter of course for a project of this size." The future-oriented expansion of the logistics center enabled Claas to create additional storage space and comprehensively restructure its warehouse processes. The logistics planning already provides for future expansions.