Wawa’s dairy convenience stores are seemingly on every major thoroughfare in the mid-Atlantic states. With 400 million customers annually, keeping the chain’s 580 stores stocked is a serious logistics challenge. Nowhere is this challenge more critical than with the warehousing and distribution of its fresh liquid milk products, as performed by the chain’s high-volume distribution center in Wawa, Pa.

Few consumer food products require as many time and temperature controls from production through warehousing and distribution to their arrival on retailers’ shelves as 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 more difficult for Wawa as its business continued to expand. The company was adding new stores, and its manually-operated chilled warehouse ran out of room. Its production 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 just 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 satisfy the need for speed and high throughput, Wawa worked with Swisslog (www.swisslog.com) Warehouse and Distribution Solutions to engineer and install a system that would meet its requirements. Swisslog put into place an 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.

High-Bay Warehouse

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 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 automated, without the need for direct human intervention.

Major benefits for Wawa’s warehouse switching from a manual to an automated high-bay chilled facility are maximized building volume and increased cost efficiency. Wawa’s high-bay can handle a greater number of crates, but in 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.

The most energy and cost efficient high-bay, chilled warehouses achieve high density 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 lift trucks, aisles can be made significantly more narrow—allowing 12-foot-wide aisles to become just 5-foot-wide. This space can then be used for more crate positions.