In 1991, the B. Braun Group's high-bay warehouse in Melsungen went into operation - initially with two storage modules and a total of 20,000 pallet spaces. The dynamic growth of the leading manufacturer of medical technology and pharmaceutical products made it necessary to plan a third module with a further 10,000 pallet spaces in the same year. OWL, a predecessor company of Swisslog AG, was used as the system supplier for the automated intralogistics of the B. Braun Group. Swisslog was again the system partner when the B. Braun Group expanded the capacity of its high-bay warehouses in 1999, 2007 and 2014. Today, the B. Braun Group's European goods distribution center has a capacity of seven warehouse modules with a total of 73,000 pallet spaces.

"Our goods distribution center is primarily a distribution center for our comprehensive product portfolio for the healthcare market," explains Uwe Gasser, Team and Project Manager for Material Flow and Logistics Projects at the B. Braun Group. The company supplies clinics, outpatient centers, medical practices, pharmacies, nursing and emergency services with a range of over 5,000 products. 95 percent of them are manufactured in-house - many plants are located near the goods distribution center in Melsungen. In terms of processes (and construction), the high-bay warehouse is directly connected to the incoming goods department and its eight manual truck unloading stations. Two further fully automated truck unloading systems can also be used around the clock. As an important player in healthcare, efficient warehouse and distribution logistics are a key quality feature of the B. Braun Group. This focus can be seen in some of the key figures for the goods distribution center: More than 13,000 square meters of total space, four kilometers of pallet conveyor systems, 2,000 pallets per day are loaded directly from the warehouse into the loading zone or directly onto trucks, and another 1,000 pallets are picked daily.

Such operations are heavily dependent on the availability of the systems used, in particular the storage and retrieval machines (SRMs). The systems run around the clock six, sometimes seven days a week. At the latest 15 to 20 years after installation, the need for maintenance and repairs increases. SRM downtimes are poison for logistics processes, as one device supplies around 2,500 pallet spaces in a high-bay warehouse, which cannot be reached during a breakdown. In order to be able to rectify breakdowns quickly, the B. Braun Group stocks spare parts for all relevant stacker crane components. But even this becomes difficult after a few decades: "The supply of spare parts becomes critical at some point when component manufacturers reduce or completely discontinue support for certain generations of their control electronics or frequency converters," explains Timo Brill, Head of Logistics Operating Technology at the B. Braun Group.

When older systems become more susceptible to wear and tear and the availability of spare parts decreases at the same time, the question of modernization arises. In addition to the complete replacement of the SRM, the partial modernization of existing systems is also an option. In such a retrofit, a stacker crane is virtually gutted and equipped with the latest technology for drives and control electronics. "In view of the very good overall mechanical condition of the equipment and racking systems, we opted for a retrofit," says Gasser. The first modernization cycle was carried out on the oldest parts of the system back in the early 2000s. System partner Swisslog also supported this retrofit: "We help to determine the ideal timing for system modernization by analysing the installed technology as part of assessments and also evaluating future serviceability, spare parts availability, failure risks and upgrade capability," explains Michael Wagner, Head of Account Management for the B. Braun Group at Swisslog.

High reliability and greater efficiency
Planning for the current system modernization began in 2017. Before the actual retrofit, the partners developed a retrofit concept that defined the goals and key points of the modernization. The aim was to avoid technical generational leaps within the ongoing modernization. As a result, the B. Braun Group team developed a specification sheet that formed the basis for the modernization and was specified right down to the operating equipment. The complexity of the goods distribution center repeatedly presents the operational technology, warehouse management and material flow planning teams with major challenges when it comes to the tasks of the individual modernization steps," says Gasser: "Only together as a team can we master these during ongoing operations.

Meticulous planning
Together with the B. Braun Group, Swisslog is modernizing 28 SRMs in the high-bay warehouse, 14 SRMs in the picking warehouse, four additional automated SRMs in the adjacent automated small parts warehouse area and a further 20 conveyor control systems in the entire goods distribution center. The new automated carousel picking system in the small parts warehouse area, supplemented by the latest shuttle technology (to expand the container storage capacity), ensures the necessary performance increases for the future. Video technology will also be installed during the renovation of the small parts warehouse in order to be able to identify and eliminate the cause of faults more quickly in future - another example of how both technical performance and processes can be modernized at the same time as part of a retrofit.

Meticulous project planning is an essential prerequisite for reconciling the retrofit activities with the ongoing operation of high-performance logistics. The B. Braun Group determines the specific sequence of modernization. Several weeks must be allowed for procurement, planning and the preparatory "starving" or relocation of the affected aisles in the high-bay warehouse. The actual retrofitting then takes place in just a few days. Swisslog's mechanics and electrical installers start by replacing motors and control cabinets or fitting them with new components and renewing the cabling, including busbars and cable chains. At the end, software engineers install the control programs and, together with the B. Braun Group managers, transfer the system to regular operation.

The current retrofit activities will take another ten years to complete. Currently, three high-bay warehouse modules have been completely modernized, as have the four SRMs in the small parts warehouse area. "If we have the end in sight by the beginning of 2030, we can actually start with the first assessments for the next wave of modernization," concludes Uwe Gasser. He says this with a smile. Because it is precisely this permanent approach that brings advantages: It keeps state-of-the-art, high-performance intralogistics at a high level and makes it possible to plan the effort and investment over a longer period of time.