Performance Up – Costs Down

MÖNCHENGLADBACH. In the dry goods sector, until 2008, Dagab AB, the Swedish supermarket wholesaler, in addition to single-line full and half pallets, mostly delivered picked-to-order consignments assembled to meet the specific needs of each individual chain store. Far-reaching market changes in Sweden and accompanying article streamlining led last year to a change in delivery tactics: the wholesalers and retailers today almost exclusively take delivery of single-article pallets whose goods are stored until use directly on site. This change required a new intralostics solution at the distribution center located in Stockholm from which Dagab primarily served markets in eastern Sweden. The existing order picking warehouse in Stockholm was to be correspondingly expanded to include a high-performance, fully automatic high-bay warehouse.

“Our logistics partner had to develop the best solution for us to be able to store maximum capacities in very limited space and to speed up transport. It was also very important to us that the system integration optimize material flow throughout the distribution center and achieve the most efficient flow of goods possible between the three warehouse zones,” reports Benny Larson, Manager of the distribution center in Stockholm. “We also took it for granted that the integration would be installed within the shortest possible amount of time and not interrupt our normal operations.” Because of their vast experience in the food and non-food distribution sector as well as a successfully integrated solution at the Dagab distribution site at Göteborg, material handling specialist DAIFUKU Europe Ltd. were awarded the contract for the project.

Japanese High-tech in Sweden

The new system consists of a six-aisle high-bay warehouse as well as conventional and high-speed conveyor technology. The warehousing system provided room for up to 12,288 slots on only 2,825 m² of storage space. “In order to accommodate the maximum number of slots in the relatively little space available, we used every available centimeter of space in all three dimensions,” reports Andreas Jablowski, Project Manager and Senior Engineer at DAIFUKU. “Another challenge presented by the project was the flexible integration of half pallets in the standard environment of the high-bay rack.” DAIFUKU determined how many slots were needed to store half pallets and prepared the middle rack aisles accordingly. Every location is flexible and can be used both to store europallets as well as to accommodate two half pallets double-deep. Even within the individual bays – a bay can hold up to three europallets or six half pallets – positioning with half or full pallets is entirely variable. “If the quantity of half pallets rises over the next few years, our solution gives Dagab the option of easily converting all of the other aisles,” Andreas Jablowski adds.

DAIFUKU installed six 15 meter high storage and retrieval units, including the corresponding aisle conveyors in the high-bay warehouse. The company also developed and implemented an efficient conveyor technology solution: Dagab uses conventional conveyor technology in the deposit and pick-up zones. This installation is linked by two fully automatic tracked high-speed shuttle cars, so-called sorting transfer vehicles (STV) to the warehouse system. The STVs serve as dual shuttles and are what provide the Swedish supermarket wholesaler with the necessary high throughput. All warehouse processes are optimized and managed by the warehouse management system Sattstore from partner Consafe Logistics which the material handling experts integrated into Dagab’s existing IT architecture. “The fact that DAIFUKU was able to provide us with all of the components from a single source was one of the main reasons why we also decided to work with this vendor at our Stockholm site,” says Christian Jensen who was responsible for implementing the DAIFUKU warehouse restructuring at the Göteborg Dagab distribution center and who was available throughout the project in an advisory capacity.

Optimized Material Flow

Working closely with Dagab, a detailed material flow analysis was produced which served as the basis for the process flow implementation: In the incoming-goods area, pallets are transferred by forklift to the conveyor which checks the contours and barcode and then delivers them to the aisle selected by the warehouse management system. In the reverse, pallets to be taken out of storage are conveyed from the respective rack aisle to the different destinations. There the goods are brought by storage and retrieval units to the locations selected by the warehouse management system. Dry goods are also taken out of storage in reverse order and just accurately and rapidly. Per hour Dagab now moves 180 pallets. “We have an hourly rate of 100 storage and 80 retrieval operations. By contract we had agreed on only 50 retrievals,” reveals Benny Larson of Dagab in emphasizing the new system’s performance. “We are profiting from an additional performance and efficiency advantage of 20 percent. This amazing result is primarily due to the heart of our installation – the STV.” And Christian Jensen from Dagab adds: “In addition to the system’s high speed of up to 200 meters per minute, using the STV means safe and reliable transport, very short transfer times, optimum use of space, and redundancy.”

To optimize material flow throughout the entire distribution center and to guarantee an efficient flow of goods, DAIFUKU create a special pick-up zone. This links both the dispatch area as well as two other manually operated storage areas.  The pick-up zone consists of a chain conveyor with a total of six dispatch lanes. Four of these lanes are dedicated to the commissioning of pallets for dispatch. One conveyor each is dedicated to both of manually operated storage areas housed in separate halls to the left and right of the high-bay narrow-aisle warehouse. “In the past, we had to replenish these storage areas by forklift. In the worst case, the drivers had to pass through all halls. This inefficient praxis has now given way to an efficient material flow thanks to the new installation,” Benny Larson of Dagab is pleased to report.

Convincing Results

Overall through the integration of the new high-bay racking system and high-speed conveyor technology, Dagab has noted the following improvements:

·       The supermarket wholesaler only needs 2,825 m² of floor space for 12,288 pallet locations.

·       The variable allocation of storage locations with full or half pallets (double-deep) gives Dagab maximum flexibility in storage place allocation.

·       At 120 percent of the contractually agreed system performance, the integrated system is extremely efficient.

·       In addition to the high rate of travel, using the STVs as a dual shuttle provides safe and reliable transport, very short transfer times, and an optimum use of space. Dual use of both STVs also provides lasting system redundancy.