Moving packages and pallets and managing an entire warehouse has several challenges for distribution center managers, such as low efficiency and productivity, high labor costs, and high safety risks for the workers. Companies should consider implementing automated storage and retrieval systems (ASRS) within their facilities to overcome most of these challenges.
The majority of material handling equipment manufacturers design and create a vast range of independent, goods-to-person ASRS. With the focus shifting from picking cases and pallets to picking up individual things, there’s been an eruption of different ASRS technologies available to help manufacturing, distribution, and warehouse operations make this change.
Here is a comprehensive guide on ASRS systems , where we look at the top types, costs, and best practices of ASRS.
What is an ASRS?
ASRS or AS/RS, short for automated storage and retrieval systems, comprises various computer-controlled systems that mechanically store and retrieve goods from pre-defined storage locations in a facility with speed, accuracy, and utmost precision.
They are a combination of controls and equipment that leverage the synergy of various technologies and vehicles to automate and dispose and retrieve high-volume goods. As long as everything is stored correctly in its set location, ASRS aids in speeding up manufacturing and shipping tasks.
Regardless of whether the load needs to be taken out from a storage unit or loaded in it and elsewhere, you can rest assured ASRS will do it accurately.
Common ASRS Systems Applications
Offering fast, compact, and reliable access to items needed for distribution, carrying stored items to the operator for quick order fulfillments, backed by software integration.
Offering high-density storage components and parts used in a manufacturing process.
Taking care of receiving inventory, group component parts for storing, and assembly kits until needed.
Offering a significantly dense storage solution for process or inventory buffering.
Offering compact solutions to briefly hold off incomplete orders waiting for additional items before shipment.
Storing sub-assemblies or work-in-progress for later use.
Dies, Tools, and Molds
Secure and ergonomic handling of heavyweight and typically costly tools needed in an automated production process.
Replenishment and Returns
Managing the inventory for returns and replenishment processes.
Maintenance and Repair Parts
Providing compact storage of maintenance components on-site to minimize downtime.
Types of ASRS
ASRS systems vary from simple manually controlled order-collecting machines working in small storage structures to significantly large computer and robot-aided storage and retrieval systems, fully integrated into a manufacturing and distribution process.
The AS/RS technologies available in the market can handle different velocities, types, and volumes of non-palletized inventory at adjustable speeds to meet fluctuating throughput demands. Mini-load and unit load are the 2 main types of ASRS.
- Mini-load ASRS like tote-stacking and case-handling systems are small robots or cranes that handle lightweight loads. They usually use shuttles or cranes.
- Unit-load ASRS is used for handling larger loads like entire pallets or cases of items. They take care of the big jobs that require moving pallets or objects weighing thousands of pounds, using either fixed-aisle or moveable-aisle cranes.
Altogether, there are eight AS/RS technologies that can be broken down into three primary categories, based on how the goods are delivered:
- Shelf-based picking – a complete tray or shelf of product is delivered to an operator.
- Bin-based picking – an individual tote or bin of product is sent to the operator.
- Automatic picking – robots are used to deliver goods to an operator.
Shelf and Tray Picking ASRS Technologies
Vertical Carousel Modules
Consisting of a series of carriers attached to a chain drive, a motor drives the bi-directional travel of the carriers in a vertical loop around a track, much like a Ferris wheel. They quickly and safely deliver slow to medium velocity items to an ergonomically positioned work counter at the operator's command.
Vertical carousel modules have the ability to offer throughputs at the rate of 100-400 lines per hour. You can easily achieve higher rates by adding batching stations and light-directed picking technologies that enable the pickup of multiple orders concurrently. Vertical carousel modules are an incredibly cost-effective and reliable form of ASRS that mustn’t be overlooked.
Horizontal Carousel Modules
The horizontal carousel modules comprise highly dense storage bins attached on an elongated track which rotates in a horizontal motion to deliver slow to medium moving product storage locations to the operator.
This particular type of ASRS can handle cases and items with a maximum weight capacity of 2000 pounds per carrier. To create the maximum throughput and picking speed, horizontal carousel modules are usually installed in groups called pods.
This enables a picker to access a product from one carousel while the others spin to line up the following required item. It yields a throughput of up to 600 lines picked per hour, attainable with light-controlled picking technologies and batching stations that simultaneously fulfill several orders. Moreover, they provide high storage density and excellent space utilization.
Vertical Lift Modules (VLMs)
VLM is the most flexible technology of this category that is engineered to adjust automatically when there’s a change in inventory. These enclosed dynamic storage solutions comprise 2 columns of trays, capable of managing up to 2,200 pounds.
The extractor/inserter in the middle automatically locates and retrieves stored trays of slow to medium pace items from both columns. They are delivered to the operator at a waist-high pick window with an impressive throughput rate ranging from 125-350 items/ hour in a standard system.
You can also integrate VLMs with refined batching stations for swiffer picking or robotic-picking technologies for fully automated operators.
The systems that store heavyweight items can be facilitated with automatic tray extractors and an overhead hoist and crane to assist operators in handling and moving their picks. The height of the products placed in each storage tray is assessed as it is put away. Hence, the vertical lift modules store the trays dynamically, barely an inch apart, to optimize storage density.
This saves up to 85% of your floor space, making VLMs an excellent technology choice for manufacturing businesses with varying inventory sizes.
Bin and Tote Delivery ASRS Technologies
Crane-Based Mini-Load AS/RS
With a single, crane-mounted handling device devoted to each dense rack aisle, mini-loads tend to carry products in trays, totes, or cases. The cranes travel on wheels or trails with quick acceleration velocities to deliver the products to the operator through a workstation situated at the aisle’s end.
The mini-load’s rack can provide either single or double-deep storage. The average height per location is 100 pounds in a single deep area and 200 in a double deep area. Perfect for slow-moving items, these crane-based mini-loads can deliver 1 load per minute for throughput rates of 60-100 lines/hour. This is an ideal high-density storage solution for businesses with over 25k SKUs or 10k totes to store.
Vertical Buffer Modules (VBMs)
The vertical buffer module (VBM) is another bin handling system created for smaller applications (under 25k SKUs or 10k totes) that usually cannot justify a huge, costly system. The VBM comprises an enclosed shelving system with a movable mast running down a center aisle to pick up and store totes.
The unit is crafted to work ahead of the operator and line up the subsequent pick for the maximum throughput. Totes can be sent over to an ergonomic turntable picking station or handled automatically through an inbound and outbound conveyor.
The equipment can also be set up with a manual station for totes replenishment during picking operations. This way, picking doesn’t need to be interrupted in between for replenishment activities.
VBMs enable you to connect multiple units through conveyors, and totes can be delivered to distant picking stations. The system is designed to be scalable, modular, and energy-efficient.
Robotic Delivery ASRS Technologies
Robotic Shuttle Systems
This system is yet another dynamic storage solution that uses robotic shuttles to travel individually from one level to another, riding on slender rails upon each storage level. They retrieve the stored items at relatively high speeds, with throughput ranging from 200-700 lines per hour. Trays, totes, or handling cases weigh between 35-110 pounds.
This type of goods-to-person ASRS can deliver significantly higher throughputs (300-1000 lines per hour) depending on the number of robotic shuttles instituted within the system. Automated shuttle systems are flexible, modular, and scalable, which means they can be further expanded with minimal structural changes as your business requires change.
Robotic Cube Storage
Robotic cube storage uses the latest automated storage and retrieval system technology. All the inventory is stored in bins and stacked inside a cube. Here, intelligent robots work at the cube’s top, where they shuffle, sort, and retrieve bins and deliver them to the port as required.
The robots work on the same cube independently, are connected wirelessly to the system, and automatically charge themselves when not in use. The software and controller act like the command center, where they provide traffic algorithms and keep a watch on everything.
Robotic cube storage systems are modular, meaning it is easy to add workstations or robots when there are fluctuations in throughput demands. In addition, it is configurable since the grid can be constructed to any size or shape warehouse.
Floor Robots (AGVs/AMRs)
This ASRS solution stores your inventory on compact storage shelving that’s retrieved and transported from storage to an operator access area by an armada of independent, mobile robots. Once the operator chooses the required item(s) from the shelf, the robot will take it back to storage. This solution is perfect for slow to medium-speed inventory.
Throughput ranges from 100-300 lines per hour, depending on the number of robots in the system. It can be further expanded by adding more robots. The average weight capacity is 1,000 pounds per shelving system. Still, it can also be increased with the heavy-duty models that can handle up to 3,000 pounds per shelving unit.
There are 2 kinds of floor robots, namely autonomous mobile robots (AMRs) and automated guided vehicles (AGVs). While they both have similar technologies, there are a few significant differences.
Guided by wires, magnetic sensors, or strips that are put onto the facility floor, AGVs are excellent for consistent and repetitive tasks. While they can identify hindrances in the route, they cannot travel off the preset path to steer around them.
AMRs have software intelligence that enables these floor robots to steer through the facility using maps (like the GPS in your car). Using the onboard maps, combined with cameras and sensors, AMRs can quickly survey the area and plan the best possible route to reach from point A to point B in the warehouse, simultaneously while steering around the hindrances in its path.
Cost of Installing ASRS
Like most warehouse automation systems, the costs of ASRScan also vary considerably. As you can see, a lot goes into designing such a system, so the prices and cost of installing ASRS systems can differ depending on your needs. Here are some of the factors that affect the final cost of an automated storage/retrieval system.
- The cost of the automated storage and retrieval system itself.
- Special handling requirements.
- Storage space
- The complexity of machine controls and software.
- Required throughput
- Operating environments (ASRS systems for cleanroom and climate-controlled environments are costlier.)
- Integration with current processes.
- Cost of shipping, delivery, and system installation.
- Cost of customizing and reconfiguring your facility and the equipment to maximize benefits.
Here are the estimated starting costs of the different types of automated storage and retrieval systems in descending order:
- Robotic Cube Storage: $1,500,000+
- Unit-load ASRS: $1,000,000+
- Multi-Shuttle: $1,000,000+
- Mini-load ASRS: $750,000+
- Vertical Buffer Modules: $150,000+
- Vertical Lift Modules: $85,000+
- Horizontal Carousel Modules: $75,000+
- Vertical Carousel Modules: $70,000+
In the following section, we observe the different elements that contribute to the cost of an entire ASRS.
What Contributes To The Cost Of ASRS?
The ultimate cost that contributes to an automated storage and retrieval system solution is the cost of technology/equipment you choose. In a highly specialized or large AS/RS, there might be a handful of upfront costs for system design and analysis to reconfigure your warehouse or facility or maximize automation’s benefits. Here are the primary factors that affect the cost of the equipment:
AS/RS usually comprise a movable component (an extractor/inserter, robotic delivery system, moveable crane) and a static storage area (racks, shelves, bins). The larger you go, the less high the cost per cubic foot is, and the moving parts are the system’s most costly part.
The storage area is static overall and less costly to expand. Hence, the cost per cubic foot significantly decreases as the unit size increases.
The environment the technology works in will also affect the cost of the unit. Climate-controlled (dry, cold, hot) and cleanroom environments will increase the cost of the unit. The facility’s location might necessitate the unit to come across seismic requirements in earthquake zones.
The cost of machine controls might differ based on the type of technology. In general, the larger the system and more moving parts, the higher the controls cost.
The inventory’s physical size, particularly extra-large or long items, might add to the machine’s cost. The weight of the stored goods may call for heavy-duty machines with more robust bins or trays.
Products that need special handling like bio-chemical products, harmful liquids and chemicals, electronics (ESD), pharmaceuticals, and food may also increase the price of the ASRS solution.
The speed needed to retrieve the stored goods all the way from the system also influences the equipment cost. The faster the throughput, i.e., time to retrieve goods/pick stored items from the system, the greater the cost.
Most AS/RS provide the essential inventory management from the onboard controls. However, you can add different levels of inventory management software for more enhanced inventory control and order picking competencies.
You can find inventory management software in tiered packages, where the cost will increase upon adding additional features. This way, you can enjoy a semi-customizable solution and avoid paying for unnecessary features.
If you want to opt for more advanced operations, you can integrate the inventory management software directly with an existing ERP or WMS system. While software integrations can be incredibly complicated, they’re definitely worth the effort, time, and cost, based on your objectives.
Delivery and Installation
The delivery and shipping of the unit from the manufacturing location to your facility and installation on-site is one of the most significant elements of the cost.
They must also consider the dismantling, disposal, and takeaway of the current system and any works that need to be done to prep the area for the new technology (relocation of sprinkler heads or ductwork, a reinforced floor, installations between floors, external installations with new enclosures, etc.).
When planning the costs of installing automated storage and retrieval systems, you must consider the unit’s location within the facility. For instance:
- Is the installation area free and clear of obstacles and easy to move around, or is it constricted and hard to move?
- Do you have easy and quick access to scissor and fork lifts, or will you need to rent and bring them to the site?
- Are the doors huge enough to get the machine parts into the installation area, or do you need to uncrate the machine outside or in another area?
After the equipment is installed comes the costs connected with implementing the new technology with your current processes. These costs mainly depend on the size of your operations and the depth of the integration you wish to achieve.
Moving beyond stand-alone automated storage and retrieval system product into more of an all-inclusive solution has significant benefits but comes at the expense of additional costs. Another thing worth considering is how to organize the parts within the AS/RS.
Typically, AS/RS solutions call for bins, totes, and dividers to efficiently utilize the space within the system and benefit from maximum productivity rates/ These can also be incorporated in the machine costs but are mostly not, so make sure to account for these.
ASRS Best Practices: Choosing the Right ASRS
To keep pace with increasing consumer demands, maintain a strong bottom line, and retain their competitive edge, you must effectively utilize every square inch of your warehouse/facility space, enhance labor efficiency, and maximize asset utilization.
To this end, many businesses choose to set up ASRS systems to automate warehousing and streamline their goods storage/retrieval operations. Here are some of the factors and features to look for.
The right ASRS must have well-designed software to support seamless scheduling of storage and retrieval operations. All the instructions to the ASRS system will be passed through this software, so make sure it is reliable, easy to use, and without technical glitches.
The right ASRS system must occupy a minimal footprint (to maximize the floor space) and feature various speed options that can manage picking and order fulfillment operations comfortably during peak demand. For e-commerce operations, systems with a high-speed buffer for quickly moving high-load volumes in or out of the storage will be best.
Height and Weight Limitations
While you can customize ASRS systems to handle practically any item, some systems are excellent for specific products. Systems must be able to take the maximum weight per unit load for your operations.
Mini-load and shuttle systems are designed for managing smaller loads (cases, totes, etc.). In contrast, unit load systems are the best option for heavier weights (drums, large totes, pallets, etc.). The vertical length should be equivalent to your facility’s overhead space. The higher you construct your ASRS system, the less expensive (per standing foot) it’ll be.
The ability to get quick, professional help is crucial to the company’s reputation and bottom line. Hence, you must always buy an ASRS from a vendor that offers prompt, reliable, and satisfactory customer service.
In case of any technical issue, a non-operating ASRS system can generate a domino effect of obstacles, unfulfilled orders, and reduced productivity that can significantly disrupt supply chains and lead to a dissatisfied customer base.
One thing is for sure: investing in automation costs significantly less than how much you are spending now. This includes picking mistakes, labor costs, returns handling, etc.
Besides, the good news is that dynamic computerized storage solutions usually give you an ROI of under eighteen months, thanks to space, labor, and picking efficiencies they offer.
Hence, businesses might profoundly benefit from a complete hybrid solution of two or more different automation technologies.