There are many ways to automate a warehouse in 2024, but Automated Storage and Retrieval Systems (ASRS) stand out as one of the most advanced solutions available today.
The Ocado Storage and Retrieval System (OSRS) is a cutting-edge cubic ASRS solution, but it’s just one of many types of ASRS, each tailored to automate high-density storage and retrieval of inventory.
This article provides a comprehensive overview of ASRS, exploring its various forms and functionalities, and demonstrating how implementing this technology can help you optimize your warehouse operations.
How does ASRS work?
An ASRS is not one solution but a category of storage technology comprising a number of individual components working together. As a result, each ASRS solution (and every individual installation) is designed and works slightly differently. In general, an ASRS is likely to cover:
Inbound and Putaway
An ASRS accelerates the process of inducting inventory into storage. This may involve human decant or be fully automated. Items may be decanted into individual items (eaches) or stored in pallets or as cases. Once inducted, items are transported by robots, robotic arms or conveyors into storage.
Putaway, as part of inbound, is a critical warehouse slotting process. A common goal is storing received goods in a highly space-efficient, accurate way that facilitates picking and replenishment. ASRS can enhance the warehouse slotting and putaway process by identifying the best location to place new stock within the storage space before physically storing it.
Learn more about OSRS’ unique, patented smart putaway algorithms.
Storage and Sortation
Once inventory arrives within the storage, warehouse execution system (WES) software and robotics are used to calculate and move stock into the optimum position, improving storage density and reducing wasted space while ensuring easy access to high-demand products.
Retrieval
ASRS can either enhance or fully automate manual picking and sortation. Systems like vertical lift ASRS deliver items directly to workstations through ergonomic pick windows, allowing strain-free access for employees.
By automating retrieval, ASRS lets employees focus solely on picking orders. Cubic ASRS, for example, uses robots to bring bins to pick stations for easy access. Since ASRS follows a goods-to-person model, employees remain at their stations while items are delivered to them, eliminating the need to walk around the warehouse—unlike person-to-goods models, where employees retrieve items themselves.
With automated shuttles, robots, or cranes handling item retrieval, ASRS ensures faster, more accurate order fulfillment, reducing human touchpoints and boosting operational speed.
Outbound
Once items have been picked, they may be packed, labeled and sorted for shipment, or returned to storage (known as ‘buffering’) as completed orders, ready for onward processing. Items may also be assembled on pallets or cages and wrapped for onward distribution.
ASRS for returns (reverse logistics)
The returns process, also known as reverse logistics, adds another layer of complexity to your operation. It requires space, resources and time for returned items to be placed back into inventory.
An ASRS can simplify the returns process and make it more efficient. Using a shuttle or cubic ASRS system, returned items can be easily routed and returned to storage while minimizing human contact after evaluation.
This ensures returns remain in the same condition as when they were inspected. ASRSs can also be used to buffer returned items alongside new stock, eliminating the need for a dedicated returns area while returns are awaiting processing.
Benefits of ASRS
Uses warehouse space efficiently
One significant benefit of an ASRS to warehouse operations is how effectively it uses the vertical space of a facility. Its compact storage space arrangements, tightly configured racks and narrow (or removed) aisles allow you to store more stock without expanding your physical footprint. There’s generally a trade-off between vertical height and floor density: some high-bay warehouses contain ASRS solutions (such as unit-load ASRS) extending vertically to heights of up to 50 meters, yet far more floor area is required for lift access aisles. Cubic ASRS typically extends to lower heights vertically (the Ocado Storage and Retrieval System (OSRS) stacks bins up to 7 meters high), yet does not require aisles—equating to far denser storage space per footprint.
Provides high accuracy
Human error is not uncommon with manual storage and retrieval. An ASRS knows where to locate and store inventory and the correct workstations to drop it off. Employees can be certain that the items they receive from an ASRS are exactly what they need to fulfill orders. Some types of ASRS utilize robotic pickers that pick or sort items with ultimate precision. Stock levels are continuously monitored within the system, so the status of every SKU is accurately recorded— from where it is to how much there is of it.
Boosts productivity
ASRS systems can automate demanding and repetitive tasks, enabling employees to focus on more engaging work and boosting overall warehouse productivity. As fundamentally goods-to-person systems, ASRSs also minimize the distance humans need to travel around a warehouse. However, the true value lies in how ASRS manages its assets. For high throughput needs, shuttle-based ASRS offers an exceptionally high pick frequency. And in cubic ASRS solutions like OSRS, robots can deliver hundreds of inventory bins to each pick workstation per hour. Additionally, our Warehouse Execution System (WES) synchronizes the movement of robots with the pick workstations to ensure inventory is always on time, achieving industry-leading throughput for a cubic ASRS solution.
Solves labor challenges
Warehouse operations present both physical and mental challenges, and growing demand on employees is deterring many from taking up work in this field. An ASRS addresses labor challenges by reducing dependence on a shrinking labor market. By taking on some of the more repetitive tasks like picking and packing, ASRS ensures smooth operations during labor shortages and/or seasonal peaks, stabilizing your throughput year-round.
Provides better stock control and security
Fully enclosed systems, such as vertical lift modules and cubic ASRS, hold items in a secure structure—preventing unauthorized and minimizing unnecessary stock handling during warehouse operations. As ASRS are mostly zero-touch by design, manual handling is not required for the storage and retrieval process. Items are only touched by employees at the point of induction and picking. This massively reduces the risk of stock being misplaced or going missing.
Timeline of ASRS adoption
1950s |
First ASRS developed by German heavy equipment industrial group Demag® (see above image). Storage structure uniquely fixed to ceiling! Inventory accessed via a lifting device. |
1960s |
Bertelsmann's 1962 warehouse featured an early ASRS with punch-card automation. ASRS primarily used for managing large palletized loads. |
1970s |
Engineering breakthroughs allowed storage racks to be built from the floor, making ASRS faster and more stable. ASRS also became capable of more complex retrieval tasks. |
1980s |
Affordable computers enabled development of inventory management software, allowing greater coordination/control over warehouse operations. This made ASRS accessible to smaller companies, furthering adoption. |
1990s |
Advanced sensors and lasers improved ASRS precision, and energy-efficient transport systems handled more diverse containers. |
2000s |
Robotics became a key part of ASRS, with automated cranes, forklifts, and guided vehicles boosting efficiency. The Internet of Things (IoT) began connecting warehouse systems, enabling data-driven decision making. |
2010s-Today |
Industry 4.0 technologies such as IIoT, Cloud computing, and additive manufacturing, are shaping the future of ASRS. These innovations continue to enable smarter, more adaptable warehouse automation to meet evolving demands. |
Types of ASRS
Vertical Carousel Module (VCM) |
This system works by rotating carrier bins in a vertical loop, like a ferris wheel. Vertical carousels are ideal for small items and can quickly yet securely transport containers to workstations. |
Horizontal Carousel Module (HCM) |
HCMs function similarly to VCMs, but (as the name implies) rotate containers in a horizontal, rather than vertical, loop. Storage capacity can be increased by stacking HCMs on top of each other. |
Vertical Lift Module (VLM) |
An enclosed system consisting of an inserter/extractor mechanism in the center and columns of trays or bins on either side. The inserter/extractor moves vertically between the columns to store or retrieve items as needed. |
Cubic ASRS (CASRS) |
Cubic ASRS stores inventory within a dense cubic grid. Ultra-high-density design and cutting-edge robot orchestration makes it the most advanced ASRS solution on the market. Robots traverse the top of the grid, moving stock bins and presenting them at workstations for picking, sorting, or replenishment. Discover Why Cubic ASRS Is the Key to Future-Proofing Your Warehouse |
Mobile ASRS (MASRS) |
Mobile ASRS systems combine the flexibility of mobile robots (automated guided vehicles - AGVs, or autonomous mobile robots - AMRs) with traditional ASRS technology. Unlike fixed ASRS solutions such as cubic ASRS, mASRS robots move between or beneath storage racks and deliver them to picking stations. |
Unit-Load ASRS |
Unit-load ASRS is an older yet still well-used type of ASRS most suited for handling large, palletized loads weighing potentially thousands of pounds. Items are stored on pallets or capacious containers. Software directs equipment to store or retrieve inventory. |
Mini-Load ASRS |
A version of unit-load ASRS for smaller, lighter loads no heavier than 75 pounds. Mini-load swaps chunky pallets for small cartons and trays to store inventory. |
Shuttle-Based ASRS |
Shuttle-based ASRS delivers inventory directly to employees at a workstation using shuttles, which independently move along a track on a rack structure. Shuttles can operate on multiple levels simultaneously, increasing overall throughput. |
What technologies does ASRS use?
Robotics |
ASRS solutions are highly reliant on robotics, which can include everything from fixed robotic arms to autonomous robots that navigate and operate independently. These robots perform key tasks such as picking, sorting, and transporting items within the storage system, reducing the need for human intervention. |
Sensors |
ASRS solutions utilize various types of sensors to perceive and interact with their environment. These sensors enable accurate tracking of items, machine positioning, and performance monitoring, ensuring smooth and efficient operations across the storage and retrieval process. |
Communication protocols |
Efficient communication is essential for ASRS to function seamlessly. These systems can use a variety of communication methods, including wired connections, WiFi, Bluetooth, and emerging technologies like 5G, to coordinate and transmit data between robots, sensors, and control systems. |
Safety systems |
Ensuring the safety of automated systems is crucial in ASRS environments. Safety protocols, fire detection, and fail-safes are implemented to protect both the equipment and warehouse operators from accidents or malfunctions, providing a secure operational environment. |
Artificial intelligence & machine learning |
AI and machine learning are growing in usage within ASRS, enabling intelligent decision-making and predictive maintenance. These technologies enhance the system's ability to learn from data, optimize storage space, and anticipate potential operational issues. |
Power systems |
Powering ASRS involves various methods, from traditional cables and battery systems to advanced solutions like supercapacitors and wireless charging. These systems ensure continuous operation of robotic assets, enabling long periods of autonomous work with minimal downtime. |
Which industries is ASRS most suited to?
A wide range of industries find significant value from automated storage and retrieval systems in their warehouses.
Fashion, Apparel and General Merchandise
- The fashion and GM e-commerce sectors experience ongoing challenges, from seasonality to high return rates.
- The exceptionally high density of a cubic ASRS makes it perfect for holding a wide range of SKUs in large quantities, making it an ideal system for fashion and retail.
- A mini-load ASRS may also provide a capable solution, especially for smaller items. However, this technology is now becoming outmoded and can suffer from single points of failure.
Industrial & OEM
- Industries such as automotive, aerospace and manufacturing often deal with cumbersome, heavy parts as well as smaller, high-tech assets.
- For small to medium parts, a cubic ASRS offers the speed and accuracy required to operate within a fast-paced automotive or manufacturing environment. Cubic ASRS works well as a post-production or pre-production buffer, as it is highly space efficient.
- For palletized loads such as heavy machinery or larger vehicle components, a unit-load ASRS provides a powerful and versatile solution, albeit at lower throughput.
Pharmaceuticals
- Pharmaceuticals have industry-specific requirements, including stringent inventory control for regulated items and strict temperature regimes.
- Cubic ASRS can provide a number of benefits to pharmaceutical operations, such as thermal controls, a secure grid and traceability.
- Vertical lift modules also offer the necessary security for inventory as the entire system is encased.
Third-party Logistics (3PL)
- The 3PL sector must store and pick goods from a variety of industries, all of varying sizes and shapes, while dealing with labor shortages.
- Cubic ASRS provides a very high density solution for storing a wide range of items, though size is limited to what can be stored within a cubic storage bin.
- mASRS solutions can be attractive to 3PL providers, as they can be installed quickly and scaled up or down with demand.
- Systems such as shuttles can alleviate those workforce shortage pressures as they automate the transport, storage and retrieval of goods.
- Shuttles can also be adapted to handle the diverse loads 3PL companies deal with.
CPG (Consumer Packaged Goods)
- A cubic ASRS offers the flexibility to store diverse SKUs at high density, ideal for fast-moving items in the CPG sector.
- Shuttle-based ASRS can also handle varied packaging sizes, providing an adaptable solution for everything from eaches up to multipacks and cases.
Grocery
- A refrigerated or temperature-controlled cubic ASRS can meet the demands of the grocery sector by securely managing chilled, frozen, or ambient items. Ocado has been successfully operating its OSRS-based Ocado Smart Platform grocery solution around the world for over a decade.
- Unit-load ASRS systems support bulk storage of cases and pallets for high-demand items
- Shuttle-based ASRS helps maintain consistent stock levels for fast-moving products, ensuring items are readily available for order fulfillment.
How important is software in ASRS?
An ASRS is only as good as its software. You could have the best hardware and physical equipment, but without the right software it’s nothing but metal and servos. The software required to do this is called a warehouse execution system (WES). It works as ‘air traffic control’ for an ASRS, orchestrating automated assets to complete storage, retrieval and picking tasks. The warehouse execution system determines what the ASRS does and where, or how, its components move. Every order is passed through this software and translated into actionable tasks. Some operations also use a warehouse control system (WCS), which is similar in functionality to a WES, but less comprehensive and sophisticated.
A warehouse management system (WMS) is also important for an ASRS. From inventory and labor management to processing orders, the WMS controls the entire warehouse operation — essentially, the high-level processes. By integrating this software with WES, they work together to elevate the warehouse operation and enable ASRS to streamline and automate the entire warehouse fulfilment process. For example, when the WMS receives information on incoming orders, it identifies relevant inventory before notifying the WES, which, in turn, directs the ASRS to retrieve the items and transport them to manual pick stations or robotic pickers.
Is an ASRS right for your operation?
This guide has explored the fundamentals of automated storage and retrieval systems, from what they are, to the different types and how they are suited to particular use cases and industries. It explains the importance of software and how it's essential to the functionality of ASRS.
Automated storage and retrieval systems can be transformative for an operation, providing unmatched efficiency and productivity. Whether you’re renovating an existing warehouse or building a new state-of-the-art facility, the modular design of more cutting-edge ASRS, such as cubic ASRS or shuttle systems, makes deployment straightforward. Essentially, they can be easily adjusted to changing business needs in future. With OSRS, for instance, you can add more robots and workstations or increase your grid’s size to deal with a wider range of SKUs and higher throughput.