Types of Automated Storage and Retrieval Systems

Nearly all warehouse operations face two major challenges: efficiently storing and retrieving inventory and maximizing their use of available warehouse space.

Automated storage and retrieval systems, commonly referred to as AS/RS, are an ideal storage solution to both of these issues. An automated warehouse with automated storage and retrieval systems can significantly increase productivity by automating inventory retrieval and procedures and condensing storage into a smaller, more accessible space.

Automated Storage and Retrieval Systems

Automated storage and retrieval systems are available in various forms; each helping warehouse operations maximize their storage space while streamlining their inventory handling processes. However, the optimal AS/RS for your operation will vary based on the nature of your warehouse and the products stored in it.

Crane-Based Unit Load AS/RS

Unit load systems are used to store and retrieve heavy or oversized objects. Unit load systems commonly transport pallets, but other containers can also be used. Many unit load systems can handle pallet racks over 1,000 lbs., with specific models capable of handling up to three tons of load. A typical unit load AS/RS can hold approximately 32 dual cycles per hour (each cycle is one storage and one retrieval), depending on the system and load.

A crane-based unit load system automatically retrieves products with an integrated rack and crane system assigned to each narrow aisle. Each rack beam is spaced appropriately around each aisle of pallets, allowing for high-density storage. The stacker crane can range in height depending on the needs of the warehouse, with some models as tall as 120 feet.

Fixed-Aisle Unit Load AS/RS

With fixed-aisle unit load automated storage and retrieval systems, an automated crane is designed to move on both the X and Y-axes while the integrated retrieval system can move across the Z-axis to manipulate pallets. Typically, a crane will be positioned at the ends of each aisle, with one for inbound pallets and one for outbound pallets. 

This system is a popular choice for warehouses with larger items requiring high throughput since they are fully automated and handle products quicker than most other storage and retrieval systems. 

Movable Aisle Unit Load AS/RS

Movable aisle unit load systems are similar to fixed-aisle unit load systems; however, the crane can move between aisles. These systems are slightly slower than fixed-aisle systems but cost less and require considerably less maintenance.

Crane-Based Mini-Load AS/RS

Mini-load automated storage and retrieval systems are functionally identical to unit-load systems, except they are designed to handle smaller loads. Most often, mini-load systems are used to manage products stored in small bags, boxes, or trays, but they can also be used for other smaller items.

Shuttle-Based AS/RS

Shuttle-based automated storage and retrieval systems are quite different from crane-based systems. These systems use pallet shuttles to handle products, moving throughout the warehouse aisles on integrated tracks built into the racking. Some shuttle-based storage and retrieval systems feature channels that allow the shuttle to move vertically and horizontally. Depending on the system model and warehouse demands, shuttle-based systems can utilize a robotic shuttle or a more straightforward tray bot system.

Typically, systems with a robotic shuttle can retrieve products much faster, sometimes reaching throughputs of 700 lines per hour. These systems are commonly found in settings where efficient space utilization is a prime consideration, such as small warehouses or micro-fulfillment centers.

Carousel-Based AS/RS

Another unique type of automated storage and retrieval system is a carousel-based system. Instead of moving the load with automated machinery, carousel-based systems move the actual storage structure with automated racking. The carousel houses the (usually smaller) products in bins, trays, or boxes and rotates the automated storage racks to allow easy access for warehouse workers. Some carousel-based systems rotate vertically instead of horizontally, which is particularly useful for warehouses with higher ceilings.

Typically, warehouses will feature multiple carousel-based systems, which allows warehouses that need to handle various open orders to fulfill them efficiently.

Shelving + Rack Supply, Inc. can work with you to develop a horizontal carousel that fits your warehouse’s needs. Our carousels increase picking rate and accuracy at a cost-effective price point.

Vertical Lift Modules

Vertical lift modules are a modularly-designed enclosed storage and retrieval system. They consist of two tray-support columns and a tray device that moves up and along the columns to retrieve products and lower them to a picking station.

These systems are used for small, lightweight items and can be integrated with inventory-tracking programs to more efficiently track product stock and consumer tendencies.

Our package-handling lifts are an ideal solution for high-paced warehouses that need to transport products between floors. Each of our package-handling lifts is customizable to fit the needs of your warehouse. They are each self-contained, OSHA-compliant, and self-supporting.

Shelving + Rack Supply, Inc. also offers a top-of-the-line vertical lift module developed in tandem with Modula. These fully-customizable, modular material handling systems save warehouse floor space, increase workflow efficiency, and feature integrated smart inventory management systems that precisely track inventory levels.

Since our modules are manufactured entirely in the United States, your system will be installed and ready to use much quicker than with overseas-based competitors.

Vertical Buffer Modules

Vertical buffer modules are an automated storage and retrieval system ideal for smaller operations that do not need more expansive systems. The system features a modular shelving system with an automated mobile retrieval cart that moves throughout the shelving system to retrieve and deliver products.

Vertical buffer modules are popular for settings with relatively small products but a high pace and volume of orders. Many vertical buffer modules are designed to maximize efficiency by beginning to process the next order before the prior order has been completed.

Another benefit of vertical buffer modules is that they allow warehouse employees to restock the shelves without requiring a pause in the retrieval process. This minimizes downtime and enhances throughput.

Autonomous Robot-Based High-Density Automated Storage and Retrieval System

Automated robot-based high-density automated storage and retrieval systems, often called robotic cube storage systems, are one of the latest developments in supply chain technology. This cutting-edge system features a cubed rack system with inventory stored inside. In addition to the modular rack-supported building, wireless smart robots use the rack system to glide to the necessary system pallets and retrieve them from the top.

The automated pallet retrieval robots work independently from each other and avoid collisions using algorithms. The robots typically charge automatically when not in use.

Since this system is modular, additional robots and racking systems can be added to accommodate the growing demands of any warehouse.

Floor Robots

Floor robots can be divided into two main types – AGVs and AGRs. Both systems are composed of a team of automated retrieval robots that transport removable shelves to a picking station. Once the warehouse employee picks the suitable object off the shelf, the floor robots return the shelf to its storage location.

AGVs, or automated guided vehicles, transport products along a predetermined path. The path is set by wires or magnetic sensors, which the AGVs cannot deviate from. While they cannot circumvent potential obstacles, they can sense their presence and pause transport to avoid collisions.

AMRs, or autonomous mobile robots, include integrated artificial intelligence software. The robot’s software features navigation tools, cameras, and sensors that allow the robot to avoid obstacles and determine the ideal path through the warehouse.

Benefits of Automated Storage and Retrieval Systems

Horizontal Carousel Pick Station

Increase Picking Efficiency

Perhaps the most time-consuming component of the warehouse picking process is walking to the product. Automated storage and retrieval systems efficiently solve this issue by transporting the product directly to the warehouse worker. This can significantly cut the time it takes to process each order.

Buffer Order Staging

Another obstacle many fulfillment centers face is constraints on the shipping window due to worker scheduling. Automated systems allow warehouses to handle orders without a full staff present, placing the order in a buffer storage area for immediate shipment as soon as possible.

Storage Efficiency

One of the primary benefits of automated storage and retrieval systems is that they help warehouses maximize their use of available storage space. These systems allow warehouses to minimize aisle space and store products efficiently, which would be impossible if the products had to be retrieved manually.

Reduced Workforce Needs

Since automated storage and retrieval systems maximize the efficiency of a warehouse’s workflow, warehouses that properly utilize these systems will require far fewer warehouse employees than they would without automated systems.

Since many automated storage and retrieval systems can be used with automated storage management software, inventory can be efficiently managed based on the individual needs of the warehouse without much employee oversight.

Our automated storage management software can also be integrated with other core business processes to allow for automatic reordering, reducing labor hours. Combined, these increases in efficiency can save operations significant amounts of money on labor costs.

Automated Storage and Retrieval Systems at SRS-I

Any warehouse operation can benefit from the increased efficiency and improved logistics provided by automated storage and retrieval systems. If you are considering optimizing your warehouse’s workflow with an automated storage and retrieval system, call Shelving + Rack Supply, Inc. at (800) 589-7225 to speak with one of our project managers and find the perfect system for your warehouse.