The WMS, which has been around for about 30 years, stores and maintains a vast amount of information including inventory data and customer orders and handles non-automated functions. It processes this data to determine things like daily associate workloads and order processing.
WCS technology came along in the mid-1990s to bridge the gap between the WMS and the warehouse floor by allocating, balancing and managing tasks executed by material handling equipment and systems in real time.
Gene Billings, director of software development for Intelligrated, said the WMS was primarily designed for batch-based inventory management and control within the four walls of a DC. WCS, he said, grew up organically on the automation side, handling real time controls of high-speed automated equipment like conveyors and shuttles.
“WMS was not well suited for light-driven solutions (LED indicators for picking items),” Billings said. “The WCS takes order-related information from the WMS, creating waves and sub-waves in the order well to get carved up and sent to the appropriate areas to get fulfilled and shipped.”
Over time, Billings said, the role of the WCS has expanded to encompass traditional WMS functions like inventory management, replenishing, slotting and receiving. “The lines are beginning to blur,” he said.
Kevin Thompson, distribution systems manager for Cabela’s, said it’s a matter of philosophy in terms of using a WMS or a WCS as the primary logic controller of DC operations. In his system stack, he said, a WMS sits on top and the material handling technology on the bottom, with the WCS in the middle.
“You could have your WCS do all of the pick/pack/ship logic, sending items to be sorted and packaged,” Thompson said. “When packaging is completed, the information on each item is sent to shipping to determine where it goes. In that scenario, all the information goes from the WMS to the WCS, and you don’t hear anything more about it until it goes out the door.”
Thompson said he prefers using a WMS as the primary logic tool because it allows him to catch a package and re-route it before it goes out the door if necessary. “If the WCS were in charge, we wouldn’t have a chance to do that,” he said.
“Some WCS implementations get very heavy, and take over a lot of the processes in the building, but we’re different from that perspective,” he said. “We like to put more logic into the WMS, and for that reason our WCS has been getting thinner over the past four years.” Thompson added that he didn’t agree with the prevailing logic that the capabilities of a WMS had to end at the DC, but could be expanded to the broader distribution network.