Until recently, PFSweb filled orders in a highly linear fashion. One picker. One order. One pick cart. One route. While that got the job done, there was definitely room for improvement.

Today, the third-party logistics (3PL) provider uses 12 put-to-light carts to fill orders for eight clients in 250,000 square feet of its Memphis DC. One worker fills multiple orders at a time with a single pass through a pick zone.

"We're all about flexibility," says Scott Talley, vice president of global distribution for PFSweb. "Now the pick path can be tailored for the order picker for greatest efficiency. Our better workers have been able to increase their productivity from 45 to 180 lines an hour."

Each cart (Siemens Logistics & Assembly Systems, 877-725-7500) has four levels on opposite sides, creating eight shelves. Items can be put to a total of 82 positions with lights.

To begin picking, the server downloads the orders to the cart's wireless terminal, which directs the worker where to push the cart first. Using a wireless bar code scanner, the worker scans both the storage location's bar code and that of the stock keeping unit (SKU). The terminal then illuminates the lights identifying where items will be put. The worker simply pushes each light to display the number of items of that SKU to be put at that location on the cart. When all the lights have been extinguished, the wireless terminal tells the worker where to push the cart next.

"These carts fit the needs of a 3PL extremely well," adds Talley.