The Ultimate Buffer System

Receiving

Incoming parts from North American suppliers arrive at one set of receiving docks (1). Another dock area (2) handles products arriving from overseas. The warehouse management software (WMS) determines the storage location for each receipt. Lift trucks gather pallet loads and take them to the assigned locations relayed through on-board terminals. Each stock keeping unit (SKU) is warehoused in only one storage area within the building at a time.

Faster moving pallets go into the automated storage and retrieval system (AS/RS) (3). Pallet loads that are too large for the automation go to conventional pallet racks (4) or are stored at floor level (5). Small items are placed into trays and sent to a separate mini-load AS/RS (6) .

The pallet load AS/RS (3) consists of eight storage/retrieval machines (S/RMs) that receive the loads on the bottom level and perform putaway within the racks of the storage unit. The racks are six deep and may be accessed from either side, which allows product to be reached even if an S/RM goes down.

The mini-load AS/RS (6) works in similar fashion, but consists of small trays to hold the parts. Up to 90% of its locations are normally occupied. Five S/RMs gather the trays and place them into the 24,000 tray locations within the system.

Other pallet loads are taken to the pallet rack area (4) and put away with reach trucks. Lift trucks deposit floor-stored loads (5) .

The enterprise resource planning system that controls plant operations and logistics calculates which parts are needed at each assembly position and how long it will take to get them there. It then signals the WMS to release the needed items.

Full pallet loads are pulled from the rack positions of the AS/RS (3) on a first-in/first-out basis. These are brought to output stations on the lower level (7) and placed automatically onto a conveyor for transport to a vertical lift. The lift raises the load to an automated conveyor mezzanine (8) where it is placed on a pallet conveyor that carries the load through a bridge tunnel (9) to the manufacturing building. Once there, another lift lowers the pallet to a distribution point where the loads are gathered by lift trucks or tuggers and taken to line-side positions.

Since the AS/RS (3) can hold pallets six deep, there are occasions when desired pallets are stored behind other products. When this occurs, the system automatically moves pallets in the forward positions to other locations until the desired pallet is accessible. The system can retrieve from either adjacent aisle, so the most that must be moved is two pallets.

Pallets may also be delivered to manual pick locations on the bottom level of the end row (10) . Workers access this bottom level and perform full carton and split carton picks onto a pallet. The pallet is then inducted onto the conveyor that feeds the vertical lift and eventually goes to the outbound tunnel.

Trays containing small cartons of parts within the mini-load AS/RS (6) are gathered by S/RMs and delivered to processing stations adjacent to the storage system (11) . Workers at the stations pick needed items out of the trays onto mixed SKU pallets that are then conveyed through the tunnel to the manufacturing facility. About 2,500 picks are performed daily from the mini-load system.

Full pallets as well as individual cartons are pulled from the pallet racks (4) using lift trucks and order pickers. On-board radio frequency data communication units receive instructions from the software to direct picking. Lift trucks select items from floor-level storage (5). Gathered loads are also inducted into the pallet conveyor for transport through the tunnel to manufacturing (9). Larger items are shipped from docks by truck to the plant (12) .

In addition to servicing the adjacent building, SKUs are also picked as repair parts for the models manufactured at Spartanburg. These are shipped to parts warehouses throughout the country (12) .

Altogether, about 12,000 picks are performed each day within the Sequence Center amounting to 2,200 pallets loads that pass through the bridge tunnel to manufacturing. A second pallet conveyor runs along the bridge in the opposite direction to return empty pallets back to the warehouse.