Conveyors: Gaining control, getting smarter
April 01, 2012 - MMH Editorial
For decades, conveyor worked as a simple mechanical mode of product transportation. You could walk into a warehouse or distribution center and see lines of conveyor running product from here to there and there to here. Today, conveyor systems do more than just transport product, they support more sophisticated tasks to save time, space and energy for DC operations.
“The goal is always to move as much product as you can with the least amount of effort, people, capital, hours or whatever the metric, in order to get product to the right person,” explains Jerry Koch, director of corporate marketing and product management for Intelligrated. When it comes to delivering product, Koch says “it’s a race for the front door.”
But increasing throughput is about more than just running the conveyor faster. Some of today’s conveyor systems can run as fast as 600 feet per minute, but what operations are seeking from these systems is control and functionality.
“The good news is that enabling technology, such as conveyor systems, have evolved and form the foundation on which new high-performance automation is based,” says Ken Ruehrdanz, warehousing and distribution market manager for Dematic. “You need more technology, not more people.”
In fact, any time a person touches a product, not only is there a cost involved, but there’s potential for error, miscounting, mislabeling and misplacing product. “The beauty of automation is that it reduces the number of touches and gets the right product to the right person in the right condition,” says John Clark, director of marketing for TGW Systems.
Advances in software
Over the last decade, a key change in the materials handling sector has been a heavy shift toward the goods-to-person principle, explains Lennard Koppelmann, director of IT for SSI Schaefer. If a company analyzes its business model, it can typically come up with a fully automated, goods-to-person solution that results in fewer people and a better ROI, he says. The question then becomes: How can I achieve better throughput at the workstations?
One answer is software. The warehouse control system (WCS) has the intelligence and capability to control the conveying equipment while the warehouse management system (WMS) has the information about the product and orders that ride on top of the conveyor. With all components of the automated storage and retrieval system communicating together, product is sequenced onto the conveyor in the right order. The WCS communicates in real time and tells the conveyor where to divert, transfer and merge product.
Conveyor is laid out in a route that minimizes travel time, but the software makes the decisions about where product should go. “Software makes flow decisions based on the operations around the conveyor and what’s happening in a picking area,” says Intelligrated’s Koch. “Totes go to a divert, or transfer point, if there are things in it to be picked,” he explains.
In a goods-to-person picking operation, the conveyor is guided by software that allows for the highly coordinated task of lining up and transporting the containers with SKUs in and out of the pick station in the precise sequence at exactly the right time for fulfillment.
With such a highly coordinated task comes the need for a more robust WCS to manage the equipment. In other words, the more you automate activity within a facility, the more the WCS has to play a role and link the conveyor to all the other systems.
The goods-to-person strategy is considered part of the outbound process because it’s all about filling orders to be shipped to customers. But, the outbound operation can only be successful if you receive, store and slot product efficiently on the inbound side and move it with as few touches as possible.