Expert Guide to Automated Storage and Retrieval Systems

Automated storage and retrieval systems (ASRS) are computer- or robot-controlled systems that can be utilized in the warehousing industry to efficiently store and retrieve goods.

Whether you’re wondering how these solutions work exactly, or trying to decide what type of ASRS to invest in, we’ll share everything you need to know in this 101 guide.

We’ll explain types, benefits and more, plus introduce you to our advanced automated solutions at Modula that will help you optimize storage, boost efficiency, improve employee safety, and more.

There are nine types of automated storage and retrieval systems:

  • Unit-Load ASRS  
  • Mini-Load ASRS  
  • Robotic shuttle-based ASRS
  • Robotic cube-based ASRS
  • Floor robots
  • Horizontal carousel-based ASRS
  • Vertical carousel-based ASRS
  • Vertical lift module ASRS
  • Micro-load (Stocker)

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What is an Automated Storage and Retrieval System (ASRS)?

An Automated Storage and Retrieval System (also known as ASRS or AS/RS) is a robot or computer-controlled technology that can retrieve or store inventory in defined warehouse locations. 

ASRS can help you save space, boost picking accuracy, and improve efficiency, among other benefits. 

Many ASRS can be integrated with various warehouse software solutions, including Warehouse Management Software (WMS), Warehouse Execution Software (WES), and more, to help you monitor and control your warehouse operations. 

An image of autonomous mobile robots
As the name suggests, automated storage and retrieval systems store and retrieve inventory automatically to reduce human workload and increase productivity

Where to Use Automated Storage and Retrieval Systems

Automated storage and retrieval systems are typically used in manufacturing, warehouses and other distribution areas.

From the automotive and manufacturing industries to retail and pharmaceuticals, ASRS redefine workflow and the use of physical, financial and human resources. 

Let’s look at the different ASRS applications: 

1. Point of Use Inventory

An automated storage and retrieval system can help optimize your workflow by safely storing inventory and quickly retrieving it when needed.

Integrating this system with your Warehouse Execution Software (WES) can determine the optimal picking, packing and shipping strategies for each order.

WES considers factors such as inventory levels, order priority, product expiration dates, and shipping requirements.

2. Goods-to-Person in the Picking and Packing Process

The manual process of walking to storage locations, and picking, packing and processing orders can be time-consuming for warehouse operators.

An automated storage and retrieval system eliminates the need for physical movement and reduces the risk of human error.

A shuttle, carousel or crane retrieves the goods you need and delivers them to an assigned workstation.

In addition, ASRS can arrange the items based on size and weight and take the floor plan and shipping zones into account.

3. Buffer Storage Management

An automated storage and retrieval system can manage buffer stock to ensure you always have an adequate supply of what you need. 

In addition, ASRS help you reduce travel time and ensure your buffer stock is secure from potential employee theft.

4. Order fulfillment

Consumers worldwide shop around the clock while expecting timely delivery.

An automated storage and retrieval system can help you streamline your warehouse operations by retrieving ordered goods and holding them in buffer storage, when orders are waiting to be shipped.

9 Types of ASRS

There are nine main types of automated storage and retrieval systems that you can utilize within your warehouse:

1. Unit-Load ASRS

Unit-Load ASRS store and retrieve bulky and heavy loads, including pallets and cases.

The weight they can handle ranges from 1,100 to 5,500 pounds (500 to 2,500 kg), while they have the ability to reach up to 100 feet.

The structure of the unit-load ASRS includes a pallet rack with narrow aisles where cranes can travel and move the pallets according to your instructions.

You can use unit-load ASRS in high-density areas with bulky loads to safely store inventory and retrieve items quickly with minimal labor.

There are two types of unit-load ASRS: fixed-aisle and moveable aisle cranes.

  • A fixed-aisle unit-load ASRS is a system that moves pallet racks in between narrow aisles. Whether moving vertically and horizontally, a fixed crane travels between the aisles to retrieve and store inventory.
  • A moveable aisle crane unit-load ASRS functions in a similar way, but the crane is not fixed and it uses a track to move between the aisles. This type of unit-load ASRS is suitable for larger facilities with more space.

2. Mini-Load ASRS

Mini-load ASRS, also known as tote-stacking and case-handling ASRS, differ from unit-load systems in terms of the weight they can handle, which is typically around 77 pounds (35 kg).

You can use a mini-load automated storage and retrieval system to store and retrieve cartons, trays, or totes in small-space facilities with many stock keeping units (SKUs).

They are also a great solution if you need to buffer and release products to picking and packing stations.

3. Robotic Shuttle-based ASRS

Shuttle-based ASRS use a robotic shuttle to deliver items without the need for human intervention.

The shuttle is powered by a battery or a capacitator. It can work on a single level or multiple levels, using a track to move between racks and transport goods to the assigned workstations.

Robotic-shuttle based ASRS travel at high speeds, with a throughput range between 200 and 700 lines per hour. This type of ASRS can handle totes, trays and cases that weigh from anywhere between 35 to 100 pounds.

4. Robotic Cube-based Storage 

Robotic cube-based storage is an automated storage and retrieval system that utilizes a three-dimensional grid of cubes to store and retrieve items. 

Inventory is stored in bins that are stacked on top of each other inside a cube. Smart robots are then placed on top of the cubes to retrieve bins and transport them to a workstation. 

5. Floor Robots 

Floor robots, also known as automated guided vehicles (AGVs) or autonomous mobile robots (AMRs) transport inventory within your warehouse to improve efficiency and reduce travel time for employees.

These vehicles are guided by magnetic strips, wires or sensors and travel along pre-defined routes set by warehouse operators.

On the other hand, autonomous mobile robots are more sophisticated robots that are equipped with artificial intelligence, machine learning and sensors to help them travel in the warehouse without human intervention.

You can utilize floor robots to transport bins, boxes and smaller inventory, such as small parts

Check out Modula’s autonomous mobile robots in action: 

Modula & MiR: automatic storage systems and autonomous mobile robots. How do they work together? 

A horizontal carousel-based ASRS consists of a track with rotating bins. The bins contain inventory that is ready to store, retrieve and transport to assigned locations.

Once you request an item, the ASRS automatically delivers the product to you, with an indicator showing the carousel and shelf where it is located.

Horizontal carousels are the ideal solution for high-speed picking in a low ceiling environment.

In either a production or distribution setting, the horizontal carousel helps save space, reduce labor costs, boost throughput and accuracy and manage inventory.

Check out Modula’s horizontal carousel in action: 

Modula HC for the US Market: the New Horizontal Carousel for Efficient Picking 

Vertical carousel-based ASRS consist of carriers that rotate vertically and deliver stored goods to the operator at an ergonomic height. 

They are primarily used to store small parts or documents. 

8. Vertical Lift Module ASRS

Vertical lift module ASRS are made of an inserter/extractor and a tray column arranged in an enclosed system. They are the ideal solution if you are looking for a goods-to-person ASRS.

Upon your request, the inserter/extractor device finds and retrieves the tray where the item is located and delivers it to your warehouse operator.

Vertical lift module ASRS allow you to store inventory regardless of shape, weight and size. 

Check out Modula’s vertical lift in action: 

Modula Lift: the vertical storage system

9. Micro-Load Stocker

If you are working in a high-density warehouse and you need an ASRS for buffering, sequencing and point-of-use goods, a micro-load stocker is the perfect fit.

A micro-load stocker consists of a series of robots running across a dense storage grid to store and pick inventory bins and deliver them to a conveyor or workstation.

There are different systems of micro-load stockers available on the market and they are typically integrated with other automated storage and retrieval systems. 

Benefits of automated storage and retrieval systems (ASRS)

From managing inventory to boosting workplace safety, automated storage and retrieval systems can help you: 

  • Make use of existing vertical and horizontal space 
  • Boost efficiency 
  • Improve employee safety 
  • Increase productivity 
  • Improve picking accuracy 
  • Optimize inventory control 
  • Speeds up order fulfillment, from receiving to shipping 
  • Reduce labor costs 
  • Reduce rental costs for extra warehouse space by taking advantage of smaller spaces 

How to Choose the Right ASRS for Your Warehouse 

Here are some factors to consider when choosing the right ASRS for your warehouse: 

  • Warehouse size and layout: Consider the size and layout of your warehouse when choosing an ASRS. For example, if your current warehouse has high ceilings, choose a vertical lift module ASRS. But if you have low ceilings, utilize a horizontal carousel-based ASRS. 
  • Inventory type: The type of inventory you store will also impact the ASRS you choose. Different systems have specific load capacities and handling capabilities. Make sure you choose a system that can handle your inventory in terms of weight, shape and size. 
  • Throughput requirements: Consider the amount of inventory you need to process in a given time frame. Select an ASRS that can meet your throughput requirements without causing delays or bottlenecks. 
  • Integration with other warehouse systems: Your ASRS must seamlessly integrate with other warehouse systems, such as Warehouse Management Systems (WMS) and Enterprise Resource Planning (ERP) systems, in order to provide you with complete visibility over your inventory. 
  • Maintenance requirements: Automated storage and retrieval systems require regular maintenance to ensure optimal efficiency. Consider the maintenance requirements of the ASRS you choose, and make sure you have the resources to perform the necessary maintenance. 

What is the ROI for Automated Storage and Retrieval Systems? 

At Modula, our automated storage and retrieval systems provide an ROI anywhere between six to 18 months. 

Factors that affect the cost of your chosen ASRS include the equipment, controls, software, delivery and installation, employee training and scheduled maintenance. The quick turnaround that our Modula solutions offer make the investment well worth it.  

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Modula’s Automated Storage and Retrieval Systems 

At Modula, we redefine your warehouse operations to ensure space optimization, improved accuracy and efficiency and increased safety, among other benefits. 

Our automated storage and retrieval systems include: 

Modula Vertical Lift Modules

If your warehouse has high ceilings and you are looking to utilize your existing space, we recommend our Modula vertical lift modules.

You can store large inventories securely and access your items at any time with a single click on the Copilot controller. Fast, accurate and safe, this simple process eliminates the possibility of errors and boosts productivity.

Choose from three VLMs: 

  • Modula Lift: Convenient for heavy loads and quick picking times, Modula Lift is the ideal storage solution for industrial products, components, and spare parts for all possible environments and industries. 
  • Modula Slim: With twice the load capacity of typical vertical carousels in a small footprint of only 32.29 square feet (3 square meters), Modula Slim can change your working environment and improve your storage and retrieval process. 
  • Modula OnePick: Fully automated while combining the strengths of vertical lift solutions and a robotic system that stores and retrieves boxes or totes, without the need for an operator. 

Modula Horizontal Carousels

If the ceiling in your warehouse or storage area is low, consider our Modula horizontal carousel.

With a picking accuracy of up to 99% and picking rates of up to 550 lines per hour for each employee, this solution will allow you to use every inch of your space while improving productivity and reducing the risk of hazards.

Boasting compactness and flexibility, Modula horizontal carousels fit perfectly in areas of complex geometry or architectural complexities.

From taking advantage of existing space to increasing productivity and beyond, automated storage and retrieval systems can improve organization, accuracy and productivity in your warehouse.

At Modula, you can select a vertical or horizontal ASRS in line with your space specifications, business needs and goals. Our solutions are safe, efficient and designed to streamline your warehouse operations.

Take your warehouse operations to another level.

Explore our ASRS.

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