Blog: The NASCAR of Zone Routing

Abel Womack recently installed a pick to light system with zone routing conveyor at one of our client’s distribution facilities. The physical layout is like an oval racetrack of conveyor with flanking pick zones on both sides. At the beginning of the shift the conveyor is started and empty totes begin to circulate around the oval track. As orders are dropped from SAP to the Wynright warehouse control system (WCS) software, they are assigned to empty totes as the license plate passes by the barcode scanners and the information is captured.

When a tote has a pick the container is automatically diverted into that zone. The pick zone operator scans the tote’s tag and the CAPS lighted display on the UNEX flow rack light up to direct the operator to the specific pick location and indicates the quantity of parts to be picked. Once the part is picked, the operator presses the acknowledgement button to verify completion. When all the lights in that zone have been extinguished, the tote is manually pushed back onto the oval track and one of two things happen. It either gets diverted into the next zone or, if the order is complete, it gets diverted to one of two pack out zones- depending on the type of order. Once an order is packed out, the tote ID then becomes available to be reassigned to another order.

This customer has two order types, regular shipments and overnight shipments. There are also two types of totes on the “racetrack”, one for each order type. Wynright software only assigns orders to the corresponding tote based on order type (regular or overnight). Overnight totes have RED markings so they can be visually distinguished on the conveyor. All associates know that RED totes must be handled first, both in the pick zones and in the pack out area.

Adjusting on Pit Road

In the middle of the oval track at about eight feet high are two 36 inch screens that give the status of the orders waiting to be assigned. A supervisor monitors this screen for bottlenecks and adjusts the ratio of regular to overnight totes based on the ratio of the orders in queue. This eliminates the need to have a full-time order injection point and requires only periodic tote-type adjustment to keep the orders flowing through the system.

Some of the flow racks are up to 20 feet deep. Bulk finished product shipments come from overseas and are replenished directly into the flow racks. This eliminates the double handling of moving product from reserve locations into the forward pick locations. Slower moving SKU’s are in divided totes on shelving with zone pick lights that display the shelving pick face location and quantity.

Finding the Groove

This “NASCAR” design has allowed our customer to put a significant number of SKU’s in a relatively small square footage while providing a very fast and accurate order picking process for a limited number of picking associates processing about 1,500 orders per day.

As consumers continue to drive the economy, it’s crucial fulfillment processes are up to speed. Not only can you reduce your company’s errors and throughput times, you’ll also rev up productivity and efficiency. Contact us to learn more.