AS/RS The Heights are Getting Higher

May 13, 2009
Systems help companies move upward as they’re moving onward.

Challenges facing the material handling industry are similar to those of other industrial sectors: surviving and even thriving during the economic storm. One viable avenue to success has been to incorporate technology solutions that offer immediate answers to current challenges and also promise longerrange possibilities for bottom-line success.

In particular, the latest generation of automated storage and retrieval systems (AS/RS) offers an effective tool for those in warehousing and distribution to achieve greater throughput, reduce errors and damage and gain better control of inventory. These systems are reaching greater heights—literally—allowing companies to expand vertically rather than horizontally, thus reducing or eliminating the expensive proposition of acquiring more real estate.

While AS/RS is not new, it has developed significantly since its beginnings in the late 1960s. Looking back at the emergence of the technology, Randall Fox, engineering manager with Daifuku America Corp., notes it began with pallet storage and rack-supported buildings. In the 1970s there were tax advantages, and even government incentives, to create large, tall buildings.

“The goal was to use less land to get more product storage in existing facilities,” he says. “They became work-in-process buffers. Actually, there is still quite a bit of that manufacturing process. It has several steps, requiring decoupling the processes. In these instance AS/RS is a good fit to store products in between processes.”

Fox observes that one motivation for companies to get AS/RS is growth. Even with difficult economic realities, if companies can see improvement in productivity and payback through worker reduction or can use existing sites to meet future demand, they can still automate.

While there is a perception that installations are only in very large facilities, that is not necessarily true. “In Asia and in particular, Japan, we do a lot of very small projects—a lot of one- and two-aisle installations,” comments Fox. “Partly, that’s because land is so expensive there. But it’s also because of the company’s culture where they don’t need one- to two-year paybacks. They’re willing to accept a four- or five-year payback. In the U.S., projects tend to be fairly large. Distribution centers move to AS/RS to stay competitive, keep labor down and increase accuracy.”

Daifuku has a broad range of products, handling loads from 10 to 6,000 pounds with standard offerings. Having installed AS/RS since the late 1960s, the company has seen many changes over the years. One in particular that Fox notes is that, in the past, AS/RS suppliers would typically be installing software for the first time as companies made the transition from paper tickets to software. Today, many companies have an ERP (enterprise resource planning) system, a WMS (warehouse management systems) and AS/RS as part of their overall software implementation.

Looking at equipment today, Fox says one of the biggest changes in AS/ RS is in high-speed throughput equipment. “That’s especially true for case handling systems,” he claims. “Each picking, case sorting and small parts buffers are requiring high throughput. So, we’re seeing two machines in the same aisle, machines that handle multiple loads at the same time. Then, with pallet handling, in addition to speed, heights are getting higher, some up to 130 feet.” Motor controls, he adds, are much more advanced than previously, as acceleration and deceleration can now be controlled. “It may be necessary to use bigger masts,” he notes, “but the controls help a lot.”

As for the future, Fox observes enhancements being made in self-diagnostic equipment that can troubleshoot itself or alert operators when maintenance is required, improving uptime and reliability. “Efficiencies come with less electricity being used and smarter designs for lighter equipment,” he explains. “There’s great focus on green projects that use less material and energy. It’s important for companies to plan for future growth and efficiency. AS/RS as a whole has become a reliable industry where projects are successful and meet the goals of customers.”

Centralizing Service Parts

While Japan has the largest number of AS/RSs, the adoption of these systems is spreading throughout the world. In Hofheim, Germany, for example, Polar, a manufacturer of papercutting machines, has incorporated AS/RS technology from Westfalia Technologies in its creation of a new warehouse for centralizing spare parts for its global network.

According to Gerwin Behrens, head of after-sales service at Polar, all parts that go to its 200 agencies in 160 countries come from the Hofheim facility. The current 15,608-square foot building was opened in September 2006, the company’s 100th anniversary.

“We had an old service parts stock facility with manual equipment,” recalls Behrens. “We had two factories in the area—the main factory and one inside the city. We decided to close the one in the city because it was difficult to maintain it in close proximity to where people are living. We decided to build this completely new building, called the Polar service center.”

Behrens estimates some 20,000 items are stored in the facility. Westfalia designed, engineered and installed a tray-based mini-load AS/RS to handle these items in 3,345 tray positions. The system is contained in two storage blocks, each with 41 levels and 41 storage channels, measuring 97-feet long by 13.5-inches wide by 38.7-inches high.

Adjacent is conventional lift truck-operated pallet storage for 1050 Euro pallets. Every single-depth channel provides one pallet position with a tray size of 51.4-inches or 50.8-inches by 24-inches. Westfalia’s storage and retrieval machine (SRM) and satellite shuttle, equipped with a pin extractor load-handling device, move in and out of the racks at speeds permitting 174 single tray loads or 87 double tray loads per hour, with a maximum of 660 pounds.

“We had no AS/RS in the older facilities,” notes Behrens. “In our main production areas, we had a similar automated system but it worked on a daily basis. Here we work in minutes. It is a totally different thing.”

In the Polar service center AS/RS operations are part of a larger system. Roller and chain conveyors transport parts from production to storage, and from storage to the dispatch area. A profile checking system ensures smooth and safe material flow. At the picking point, a weighing station and barcode scanner gather precise data, which is then available online to the dispatch department.

Since implementation of the AS/RS system, shipments have grown 300%, to some 150 daily. “In the past we shipped parts only to our agencies for their stock,” explains Behrens. “We would make big shipments. This has changed totally. Today we have many more shipments because we now ship parts directly to the customer.”

Polar has improved its processes so that a number of its agencies in Germany, France and other European locations have been able to reduce their inventories. “That was one of our major targets when we began this program,” Behrens says. “Our shipping process is so quick now they don’t feel the need to stock every item. They can send the order to us at the Polar service center, and we ship it to the customer, with no difference from the customer’s point of view.”

Automating to Consolidate

Fresenius Medical Care, another German company, chose to build a new, automated facility, not only to answer its present needs but to provide for its growth over the next 10 to 15 years. Fresenius, a provider of dialysis products, has a network of more than 2,000 dialysis clinics in North America, Europe, Asia, Latin America and Africa. For the project it engaged the services of LTW Intralogistics.

The new, high-bay warehouse replaces two conventional distribution centers. To serve its global market, 70% of all articles in the new facility are exported as full pallets to 140 countries. Within the Central European market, most items are shipped as consolidated orders to other warehouses, hospitals or individual patients.

The fact that most shipments are by full pallets drives the need for automation, with AS/RS used for small parts. For the small parts, there are two rack lanes featuring double-deep storage. There is space for 8,700 plastic boxes. There are two aisle-bound SRMs with a driving speed of 300 meters per minute and a hoisting speed of 180 meters per minute.

The entire warehouse has seven aisle-bound SRMs, operating in two shifts, that permit handling of 4,500 pallets per day. As for future growth, there is the possibility of adding three rack lanes.

AS/RS operations are part of an organic whole within the high-bay facility. LTW terms the software that communicates with the Fresenius WMS a "mobile manager." The WMS coordinates the different SRMs and conveyor system. The system’s human machine interface (HMI) functions as the system motion controller.

Increasing Capacity

There is also a German AS/RS connection in the creation of the new Phoenix Contact DC in Harrisburg, Pa. The company’s parent is located in Germany as is that of viastore Systems Inc., the supplier of the automated material handling operations in the facility. In fact, one of the reasons viastore was chosen was because of Phoenix Contact’s experience with AS/RS in Germany, according to Lou Paioletti, the company’s director of logistics.

Phoenix Contact is a manufacturer and distributor of electrical connection, electronic interface and industrial automation technologies. The new DC is its only one in the U.S., with most shipments going to domestic locations, although there is some business with Canada, Mexico and Argentina. Components are shipped to the company’s manufacturing plant, as well, located directly across the street.

Within the building are four AS/ RS aisles in which are stored 44,000 totes of product, weighing as much as 66 pounds each. Each tote is 15.75-inches wide by 23.62-inches deep by 7.87-inches high. Four AS/ RS machines are used in the aisles, and each machine is equipped with a double-deep lateral belt transfer load-handling device for storing totes two deep into the racks.

A tote-handling conveyor system includes vertical sequence buffers that feed workstations for picking and packing. There’s also an automatic robotic combination tote depalletizer/palletizer. In depalletizing, the system unsticks pallets of incoming product in totes. Palletizing stacks pallets of empty totes destined to return to the manufacturing facility in Germany from which they arrived.

As far as storing product inside the totes, Paioletti explains, “our internal rules are four different SKUs per tote.” He points out that theoretically the software could handle an infinite number of SKUs per tote, but it was programmed to allow only four per tote.

In reflecting on the configuration of the 51,200-square foot building, Paioletti says, “the footprint of the building would allow 12 aisles in total. We could probably put another four aisles in without considering building expansion.” As it stands, the building is sufficiently large so it could add storage capacity for another 88,000 totes in eight additional AS/RS aisles.

“All of the software on the WMS was done in house by viastore,” notes Paioletti, including material flow control software with visualization as well as WMS software that interfaces Phoenix Contact’s Baan ERP software package.

One of the benefits Paioletti has found with the AS/RS has come in the receipt of product. “Every week, we receive at least one 40-foot ocean container from Germany,” he explains. “All product comes to us in grey totes. Prior to going with the AS/ RS, it would take seven people over two shifts—with interruptions— about three days to put away the contents of the ocean container. Now, it takes two or three people six hours to put away an entire 40-foot container.”

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