One man's loss is another man's gain.

That's what happened when Rittal Corp. transformed an empty warehouse in Urbana, Ohio, into a state-of-the-art manufacturing plant and distribution center for computer and electronic enclosures.

Built in the late '80s to store household products for another company, the 512,000 square foot facility included conventional rack storage and a four-aisle, high-bay, rack-supported automated storage and retrieval system (AS/RS) that had been dormant for several years. But with business rapidly expanding, Rittal needed to expand its production lines.

The remodeled facility produces more than 2,000 enclosures a day. But the heart of the operation is the AS/RS, which was retrofitted with new input and output conveyors, two shuttle cars, and upgraded controls (viastore systems).

The AS/RS storage racks, with nearly 7,000 pallet-storage locations, were modified to accept a 48 x 32 inch European pallet. Finally, a new warehouse management system (WMS) was installed to manage the facility along with a materials handling control system to manage the AS/RS.

'The AS/RS has dramatically improved our control of finished goods inventory,' says Arthur Zheng, Rittal's distribution manager. 'The system automatically handles our storage needs without hunting for the product you need. Pallets are put away or retrieved at the push of a button.'

Headquartered in Springfield, Ohio, Rittal is a subsidiary of Rittal International, a German-based manufacturer of enclosures for manufacturing facilities and data centers.

The company purchased the vacant Urbana distribution center in 1998. Initially, Rittal used the facility strictly as a warehouse. Finished goods were stored on the floor or in the 11,000 pallet locations of conventional rack.

'We had 20 trailers a day running between our plant in Springfield and the warehouse,' says Zheng. 'Getting finished goods from one location to the other was a battle.'

What's more, the paint line in the Springfield plant couldn't keep up with the growing demand, Zheng adds. Rittal needed to expand and modernize.

The solution: combine both activities in Urbana, and free up floor space for manufacturing by retrofitting the AS/RS.

'Before we could store inventory all over the building,' says Zheng. 'But with the manufacturing line coming in, we had to use all of the space, including the height of the building. It made sense to retrofit the AS/RS.'

New conveyor, shuttle cars and controls modernized the unit. The new WMS and materials flow control system provided real-time visibility and inventory control inside the warehouse.

The original design accommodated 48 x 40 x 54 inch loads. The system was modified to feature 6,904 pallet locations, each handling smaller but taller loads that measure 48 x 32 x 79 inches and weigh up to 1,323 pounds.

The system measures 546 feet long and 85.5 feet tall, making best use of the cube.

The four S/R machines run at a maximum horizontal speed of 525 feet per minute, and a vertical speed of 131 feet per minute. The shuttle cars can travel at 1,000 feet per minute.

Click here to see layout diagram

To initiate the manufacturing process, sheet metal is delivered to the fabrication line by lift truck. There it is roll-formed into skins and frames that are then robotically welded. Skins and frames are then delivered to the paint line by lift truck.

The unfinished parts are attached to hangers on an overhead chain conveyor system that transports them to the paint line. Rittal's finishing system includes five powder paint booths with laser-monitored robotic applicators able to paint 2,000 cabinets per day.

At the end of the paint line, enclosures are manually removed from the overhead conveyor and taken by hand to the assembly area. There, parts and hardware are assembled according to the product line. Roller conveyor links workstations.

Completed cabinets are loaded and stretch wrapped on 48 x 32 inch pallets.

Once bar code labels are printed and applied to the pallet, the load is ready for storage.

Finished enclosures can be stored in the AS/RS or conventional rack storage. Odd-sized enclosures are delivered to an over-flow area. Another area is used for floor storage as needed. All inventory is managed by the WMS on a first in/first out basis.

When a lift truck driver arrives at the assembly area to pick up a load, he visually reviews the bar code label, which includes information about where the load will be stored. The label is then read with an onboard scanner to confirm the pick up.

The WMS chooses an empty location for pallets assigned to the rack storage area. After storing the pallet away, the driver scans the location to confirm putaway. The WMS is updated in real time, and the inventory is immediately available for delivery.

The lift truck driver delivers pallet loads that will be stored in the AS/RS to the input conveyor, where a bar code is automatically read by a stationary scanner. That enters the inventory into the WMS, which chooses a putaway location. The load is also checked for size, and then conveyed to one of two shuttle cars for transportation to the input conveyors in front of the AS/RS. There the load is picked up by the appropriate S/R machine and delivered to its storage location, where it is available to be picked.

During normal operations, the AS/RS can store or retrieve one load every two minutes, says Zheng.

On the outbound side, the process works in reverse.

Orders to be filled are printed and distributed by a shipping team leader to lift truck drivers. If an order is coming from conventional rack storage, a lift truck driver scans the location after removing the pallet to notify the system that the location is available for storage. The pallet is then delivered to a shipping holding area. There, a dock employee visually verifies the order, prints out shipping labels, and loads the pallet onto a truck for delivery.

Loads retrieved from the AS/RS are deposited on outbound conveyors that transport them to a shuttle car. Pallets can be delivered to any of four possible pickup locations, where they are queued until they are retrieved by a lift truck driver. They are then delivered to the shipping holding area and loaded onto a truck for delivery.

Two years after going live, Zheng says the AS/RS has improved the accuracy of inventory, and significantly reduced the time to deliver finished enclosures storage to the shipping lanes.

'Thanks to the AS/RS, we have better inventory control than we have ever had,' he says, 'and we are able to make better use of the cube of the building. It's been a huge advantage.'

Click on the icon to learn more about AS/RS systems in a manufacturing plant.