To help keep its stores stocked with fresh products, Wawa’s high-volume distribution center sports a high-bay chilled warehouse serviced by 16 fully-automated mini-load stacker cranes and a warehouse management system from Swisslog, allowing the dairy to move 42,000 crates of liquid products daily with an accuracy rate exceeding 99.9%.
by Patrick Roberts, Contributing Editor
The name Wawa is well known throughout the mid-Atlantic states. Its dairy convenience stores are seemingly on every major thoroughfare, and with 400 million customers annually it presents a serious logistics challenge to keep the stores stocked. Nowhere is this challenge more critical than with the warehousing and distribution of its fresh liquid milk products. Few consumer food products require more demanding time and temperature controls from production through warehousing and distribution to their arrival on retailers’ shelves than dairy products. Fresh liquid milk must be distributed within days, and some of Wawa’s milk products are moved through its distribution center and shipped within a few hours after being filled and packaged.
The Need for Automation
Achieving this speed of throughput became increasingly more difficult for Wawa as its business continued to expand. The company was adding more new stores, and its manually-operated chilled warehouse had run out of room. Its production had outpaced its storage capacity. The company’s products were now being produced, staged on the warehouse floor and quickly shipped to make room for milk, teas and juices that were newly coming off the line. The distribution center’s storage space had surpassed maximum capacity and it was running out of space on the floor to stage products.
“The challenge was where to put the product,” says David Mann, manager of Wawa’s Beverage Warehouse. “Where do you store it? Basically, the plant would produce to ship. It wouldn’t ever produce more than could be shipped over the next day. There wasn’t any more room on the floor to stage it.”
To find a solution to this logistics challenge, and facilitate the need for speed and high throughput, Wawa brought in Swisslog Warehouse and Distribution Solutions to engineer and install a system that would meet the company’s demanding requirements. Swisslog put into place a streamlined and highly automated storage and distribution solution that would provide adequate storage capability and better ensure timely and accurate handling for all of its liquid products including milk, teas and juices.
Wawa’s solution focused on building a high-bay refrigerated warehouse, serviced by 16 high-speed, fully-automated storage and retrieval mini-load stacker cranes that efficiently move crates in and out of the 35-vertical-foot, high-bay racking. The high-bay/mini-load system receives crates filled with milk, teas and juices from upstream production, stores up to 80,000 crates in the system, then selects and releases crates to fill pick orders for shipping. The storage and retrieval functions are performed completely automated, without the need for direct human intervention.
There is a major benefit for Wawa’s warehouse switching from a manual to an automated high-bay chilled facility, and that is maximized building volume and increased cost efficiency. Wawa’s high-bay can handle a greater number of crates, but on a much smaller footprint. Of equal importance, the footprint reduction becomes an increasingly important factor in energy
savings since much of the cold loss in a chilled warehouses occurs through the roof. Chilled warehouses are giant insulated refrigerators which extract heat to produce a chilled environment. The removal of heat comes at a hefty energy cost. Having a smaller roof footprint in a refrigerated warehouse presents a considerably better energy solution.
Those high-bay, chilled warehouses that are the most energy and cost efficient have achieved a high density of space utilization. This means they have a space configuration that allows for the maximum number of crate positions to fit into the facility.
Wawa’s high-bay optimizes cubic space usage, not only by its vertical stacking capability, but also by minimizing aisle cubic footage. By eliminating the need for forklift trucks, aisles can be made significantly more narrow — allowing 12-foot wide aisles to become just five-foot wide. This space can then be used for more crate positions.
Wawa’s distribution facility can automatically handle 42,000 crates of liquid products daily, operating with a system uptime rate exceeding 99%, and an order accuracy rate topping 99.9%, while functioning in a chilled 35-degree environment.
For a more detailed look at Wawa’s distribution warehouse, stay tuned for the July issue of Convenience Store Decisions.