Automated Storage and Retrieval Systems (AS/RS) are not new technologies. They actually became commercially available in the 50’s and 60’s by firms in Europe, the United States and Japan. Since then, there have been vast improvements in computer systems, electrical controls, supercapacitors and pallet design standardization that have contributed to lower cost equipment and a vast array of possible applications. Is an AS/RS right for your warehouse? Let’s dive into this technology to find out.

What is an AS/RS?

AS/RS encompass a wide range of products now in use, like carousels, vertical lift modules, and fixed aisle storage and retrieval systems. I am going to focus on the storage and retrieval systems as they are the most practical for automating an entire warehouse.

The basic components of an AS/RS are:

• Storage and retrieval machines
• Rack structure
• Conveyor (or AGV) interface
• Warehouse Control System

Storage and retrieval machines are designed to handle a wide range of load types, but for the typical warehouse, this usually means pallet loads, individual cases or totes, or both. An entire AS/RS design is focused on the load handling (dimensions) and speed of delivery for a particular load type. Key to the successful operation of the system is the passing of load movement information between the existing Warehouse Management System and the automated Warehouse Control System (WCS).  This WCS manages all of the automated equipment functions and tracks load movements into and out of the system.

Pallet Load Handling Options

In a pallet handling system, the most common configuration is a fixed aisle storage and retrieval machine that moves the pallets into and out of storage locations. These storage and retrieval machines can also incorporate shuttle cars for deep lane storage, and there are versions that can automatically change aisles. Less common, but very successful in the right applications, are pallet lifting or lowering devices that move loads between levels in the racking as well as shuttle vehicles that move pallets into and out of storage locations. This wide range of options allows an AS/RS to be configured to match any load type, SKU density profile, and speed of delivery.

Case and Tote Handling Options

There are even more types of carton or tote handling systems. The same stacker crane equipment used for pallet AS/RS has been scaled down to provide the traditional approach.  This storage and retrieval machine is similar in function to the larger pallet handling system: aisles are fixed, a crane traverses the aisle and retrieves and stores totes as needed. Other, newer types of tote handling AS/RS use shuttles cars and even lifting robots. These have been coined goods-to-person systems.

What are the benefits of AS/RS warehousing?

The biggest gains an AS/RS offers in a warehouse are reducing the use of space and labor.  The load handling tolerances are only limited by the uniformity of the pallet loads stored in the system. The only fixed requirement is the need for a rack structure.  This could range from single, double or triple deep with a fixed mast shuttle, or a deep lane configuration with an autonomous shuttle that drives off of the crane.

An AS/RS can either be a standalone structure inside of an existing building, or it can be designed as a “rack-supported” structure, where the building wall panels and roof are attached to the outside of the rack structure, making a denser footprint and possibly reducing over-all building, AS/RS costs.  This approach is commonly used for cold or freezer storage as well as large-scale, greenfield warehouses.

Labor savings are the result of quantifying all of the load handling movement labor displaced by the equipment. Keep in mind, this type of equipment is most cost effective when it operates for multiple shifts.  In many ecommerce applications, the use of tote handling AS/RS solutions is the only way to match the speed of order fulfillment with real-time order demand.

Other ASRS benefits include:

• Consistent handling of product in a safe and secure manner
• Storage putaway rules managed by the WCS are always followed
• Real-time product tracking and identification is maintained
• Automated replenishment can facilitate order picking and consolidation
• Highly controlled storage environment, insuring no human access

Sorting Through the Options

Bastian Solutions’ consulting group has knowledgeable experts who can work with you and your team to explore the possibilities for AS/RS in your warehouse. We can leverage our firm’s expertise with almost all of the leading technologies to find the best fit for your SKU profile, storage quantities and throughput needs.  We can also let you know if AS/RS simply is not the best fit for what you are trying to accomplish and what you should pursue instead.  

Learn more about Automated Storage and Retrieval Systems (AS/RS)

Author: Mike Clemens