Automated Storage and Retrieval Systems (AS/RS)
Automated storage and retrieval systems (AS/RS) are inventory management systems that are widely used in distribution centers and warehouses throughout the United States and the world. AS/RS systems generally consist of machines that move up and down one or multiple parallel storage aisles, storing and retrieving products and materials for dissemination to internal and external destinations alike. The advantages of these systems are numerous. They provide users with increased inventory control and tracking, including greater flexibility to accommodate changing business conditions. Indeed, these systems are comprised of modular subsystems that can be easily replaced to minimize downtime and extend the service life of the overall system. AS/RS systems also reduce labor costs, lowering necessary workforce requirements, increasing workplace safety, and removing personnel from difficult working conditions (such as cold food storage environments). Perhaps most significantly, however, AS/RS systems can produce major savings in inventory storage costs, as vastly improved warehouse space utilization—both vertically and horizontally—creates greater storage density.
Automated storage and retrieval systems do require considerable investments of a company's resources, however. "Maintaining highly integrated systems requires training and experience and is not without occasional frustrations," noted Michael Wigington in Plant Engineering. "Even the most experienced AS/RS user struggles to support the changing requirements of maintaining aging technology and tired mechanization." The cost of purchasing and implementing an effective automated storage/retrieval system is significant as well, encompassing everything from pre-purchases analysis of supply chain and inventory management needs to the actual purchase price of AS/RS equipment and software. In addition, experts in the use and maintenance of AS/RS systems note that companies often experience significant ongoing costs for maintenance and updating of various subsystems. These capital expenses can tempt some business owners to cut financial corners, buying "bargain" systems that are ill-equipped for extensive, long-term use. In many cases, such decisions can end up costing far more in the long run. "A long and reliable service life [for an AS/RS system] begins with procurement, not maintenance," wrote Wigington. "Light-duty storage systems are particularly vulnerable by failing to deliver well-engineered equipment and software. These systems require a high level of upkeep and experience a sticky, entangled web of mechanical, electrical, and software problems." When such disruptions occur, the impact can be devastating to small and mid-sized businesses. The toll of interrupted AS/RS service extends from the measurable (lost production and shipping revenue, increased labor costs for repair) to the intangible (diminished workforce confidence in the company's operations, downgraded client confidence). As a result, businesses are urged to examine the long-term implications of their choices when they incorporate an automated storage and retrieval system into their operations.
Further Reading:
Feare, Tom. "Staging/Storing: Up, Down, and All Around." Modern Materials Handling. February 2001.
Poirier, Charles C. Advanced Supply Chain Management. Berrett-Koehler, 1999.
"State of the Art in Automated Warehousing." Diary Foods. March 1999.
Van Denberg, Jeroen, and A. Gademann. "Optimal Routing in an Automated Storage/Retrival System with Dedicated Storage." IIE Transactions. May 1999.
Wild, Tony. Best Practice in Inventory Management. Wiley, 1998.
Wingington, Michael. "Five Prescriptions for Creating a Successful AS/RS." Plant Engineering. August 1998.
