Providing quality car products at a low price has built Discount Auto Parts into one of the nation's fastest growing parts retailers. After successfully expanding throughout its home state of Florida, DAP began putting down roots in neighboring southeastern states. The company soon realized, however, that its Lakeland, Fla. distribution center would not be able to support all of the new stores.

'It's a long way to deliver from Lakeland to Louisiana,' says Roy Martin, vice president of supply chain and logistics.

After evaluating its distribution processes, a second facility was built in Gallman, Miss. The new DC allows DAP to reach new stores in its westward expansion, including the Texas market. The chain currently has 663 stores with about 30-40 coming online each year.

'In Lakeland, we have seven high-volume conveyor lines merging into one. It's like the LA freeway at rush hour with all the resulting bottlenecks,' notes Martin. 'The building itself is a hodgepodge of four different expansions built over 20 years. So, we decided to try some new automation approaches here in Mississippi.'

Open only since March, the new center has already begun to lap the overburdened Lakeland facility. Central to the DC's effectiveness is a unique system that combines a pallet carousel, gantry unit, and stretch wrapper that together build pallets of case picks. This system is over 500% more efficient than the case picking methods at Lakeland - 1,000 picks an hour compared to Lakeland's 170.

Additionally, picking from pallet flow racks in the new facility is 70% better than in Lakeland, while full case picking from case flow racks is 44% more efficient. Much of this is due to an extensive use of pick-to-light technologies.

Labor costs have also been reduced due to the automated systems, while staff training has been made much easier. Gallman currently serves 161 stores with more being added monthly.

Installation and integration went very smoothly, overseen by DAP's construction manager Randy Peters.

Much of the credit also goes to Discount Auto Parts' choice of an equipment manufacturer (FKI Logistex, www.fkilogistex.com) that offers a wide range of key materials handling solutions - including the gantry, pick-to-light systems, conveyors, sorter, carousels, and the midlevel software systems that connect between the warehouse management system (WMS) and the individual machine controls. This was one of the first major cooperative projects for the FKI brands since its acquisition last year of Pinnacle Automation.

UPC codes on receipts are scanned with radio frequency data communication (RFDC) units upon arrival at the facility's 25 doors. Workers also scan and attach license plate labels to each pallet.

Most receipts are taken by lift truck to pallet rack storage with a few exceptions. Items for the bin carousels go to racks and shelves adjacent to the carousel pods to ease replenishment. Pallet loads of the 16 top stock keeping units (SKUs) are staged in 16-deep pallet flow racks next to the gantry/pallet carousel system. Occasionally items are also needed immediately for picking. In these in-stances, receipts may be taken directly to the bin carousels or to the multi-level pick modules that house full and broken cases of SKUs in pallet and case flow racks.

Replenishment occurs during the second shift with about 10% of the pick modules re-stocked daily based on a min/max formula. Lift trucks pull full pallets from rack storage as directed by onboard RF units. These are transported to the pallet flow racks within the pick module. Pallet loads are also pulled by lift trucks from the flow racks next to the gantry and taken to the automatic input stations of the pallet carousel.

Meanwhile, order-picker trucks pull split SKU loads from reserve storage to restock the case flow racks and bin shelving of the pick modules. Order pickers also gather items from racks near the bin carousels to replenish those units.

Picking takes place the following morning after replenishment with a typical day's processing grouped into seven waves. The gantry/pallet carousel unit handles the fastest full-pallet SKUs. The bin carousels process medium movers, while split-case fast movers are picked from the pallet and case flow racks. Slow movers are stored in shelving within one of the pick modules. The facility also processes security items and aerosol products in separate areas that offer greater protection and safety.

Where items are slotted, or placed within the DC's processing areas, is crucial to effective management of DAP's distribution costs.

'We will make or break productivity here based on what we do with our slotting and inventory control,' adds Martin.

The gantry/pallet carousel unit revs up each morning at about 4:00 am. It is located next to the shipping dock to ease outbound flow. To visualize the pallet carousel unit in action, think of The Whip amusement park ride. Each of the two pods consists of 32 wheeled carts pulled around an oval hub. Together, they hold 64 pallets of the fastest-moving large-item SKUs, such as cases of motor oil, antifreeze, and washer fluid.

As a pallet cart to be selected approaches the loading position for the gantry, the pod stops rotating. The gantry uses vacuum lifters to lift the top layer from the cart and carries it to one of three pallet-build positions. The carousel then moves again to bring the pallet containing another pick into position while the gantry selects a layer from a cart on the second pod.

The three pallets being built each represent a store. Some may receive only a layer or two of these SKUs while others may receive five or six layers. Those pallet loads with only a few items will be later cubed by adding additional selections from the pick modules.

Once all picks for a store have been deposited onto the pallet, it is conveyed to an automated stretch wrap station. After wrapping, the unitized load is picked up by a lift truck and staged at the dock until all products from the other areas of the DC have been gathered for that store.

The entire gantry/carousel/wrap station is so automated that it requires only one employee to operate and monitor, yet picks a high rate of 1,000 cases an hour.

With the exception of the gantry and non-conveyables area, pick-to-light systems are used for selection of all other products at Discount Auto Parts.

'The beauty of pick-to-light is that it is difficult to make a mistake,' says Martin. 'Our people get up to speed very quickly with it.'

The two-level bin carousels consist of seven pods with four carousels per pod. The 28 units contain a total of 36,080 potential storage positions. However, it is currently configured for 19,000 with some locations doubled or tripled in size to hold more product and thereby reducing the need for constant replenishment.

Pick tickets are first scanned to initiate picking, causing the carousels to spin to needed storage locations. Lights show the exact shelf and quantity of SKUs for required items. These are pulled and placed into nine staged totes with each representing a store. The tote is then pushed off onto a take-away conveyor. Most will head directly to the shipping sorter with the exception of the last tote of a store order. If not completely filled, the tote will pass to the broken case picking area for additional selections.

Two, three-level modules comprise the forward pick area. Pick module 1 holds broken-case items. Pick-to-light is used here to select items into eight red totes at a time. These ship directly to stores on a returnable loop. Pick labels are scanned to initiate the picking process. A lighted display on the racks indicates the SKU and quantity to be selected. These correspond to lights that also illuminate next to individual rack locations.

Pick module 2 contains pallet and case flow racks. Similar to the broken case items, full cases are selected by scanning a pick ticket and then following the instructions of pick-to-light displays and lights attached to the pallet flow racks. Workers attach store labels to the cartons as they place them onto a belt that runs through the module.

The module also holds small carton items that are pulled from the flow racks, also using pick-to-light. Some are able to ride the conveyor directly. These receive a store label and are placed directly onto the belt. Smaller items are pulled from the flow racks and are placed into blue processing totes for better transport on the conveyor. The upper level of module 2 also holds slow moving parts on shelving, such as items for collector cars.

High-security items are housed in a separate area that protects their value. These items are picked onto carts, again using pick-to-light technology. Workers scan pick tickets that cause displays on the portable carts to illuminate showing the quantity and SKU to select. The worker then scans a bar code on the shelf where the SKU is located to confirm the pick. Lights on the cart also illuminate next to the nine totes found there to indicate where to place the pick. Again, each tote represents a store. Filled totes are placed on a take-away conveyor.

Aerosol products, such as spray paints and cleaners, are also kept in a separate area to isolate their fire hazard from the rest of the facility. Carts utilizing pick-to-light process these orders in the same manner as picks in the security area.

Non-conveyables are stored in pallet racks. Order-picker trucks select these items as directed by RF devices. Large picks are pulled and labeled, while small items are gathered into totes. Picks are then taken directly to shipping.

Other than the non-conveyable selections and cases pulled by the gantry, all other cartons and totes are routed to a sliding shoe shipping sorter that diverts products to ten shipping lanes. The cartons, red totes, and non-conveyables are stacked together onto pallets for shipment to stores. Small boxed items are removed from the blue totes and added to the stack. Full pallets are then wrapped and staged until ready to be loaded at the 25 outbound docks. Discount Auto Parts uses its own fleet of trucks.

Martin and his team are slowly pushing more product into the building as stores are added to the distribution list. Eventually, more than 450 stores can be served from Gallman. The facility was also designed to double in size.

'This is still very much a start up operation,' he says. 'We need more volume to see what it can really do. It is like a sports car that is capable of going 160 miles an hour but is only doing 30 now.'

Even so, the facility has already met its design objectives. Martin adds that while the automation creates rather complicated processes within the DC, he hopes that it permits distribution to appear to the stores as a simple and routine operation.

'We are a retail company, so distribution is a back room function,' he says. 'Our job is to bore the retail stores with our consistency. When we have done that, then we have succeeded.'

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