Automated Storage and Retrieval Systems (AS/RS)
Automated Storage and Retrieval Systems (AS/RS) are computer-controlled systems that automatically place and retrieve loads from set storage locations in a facility with precision, accuracy and speed. They are designed for automated storage and retrieval of parts and items in manufacturing, distribution, retail, wholesale and institutions. Originating in the 1960s, AS/RS initially focused on heavy pallet loads. With the evolution of technology, the handled loads have become smaller.
Retrieval of items is accomplished by specifying the item type and quantity to be retrieved. The computer determines where in the storage area the item can be retrieved from and does the retrieval. It directs the machine to the location where the item is stored and manages the machine to deposit the item at a location where to be picked up.
Automated Guided Vehicles
A system of conveyors and or automated guided vehicles are sometimes part of the AS/RS system. These take loads in and out of the storage area and move them to the manufacturing floor or loading docks. When you want to store items, the tote (or tray) is placed at an input station for the system. It is followed by information and/or inventory input into the computer terminal.
After that, the AS/RS system moves the load to the storage area, determines the location for the item, and stores the load. As items are stored into or retrieved from the racks, the computer updates its inventory accordingly.
Having an ASRS in a warehouse includes multiple benefits such as: improved overall throughput, fast-paced order turnaround, improved labor retention and resiliency, increased high storage density, and increased floor space.
Within the storage, items can be placed on trays or hang from bars. These items are attached to chains/drives in order to move up and down. The equipment required for an AS/RS includes a storage & retrieval machine (SRM) that is used for rapid storage and retrieval of material. SRMs are used to move loads vertically or horizontally. The retrieval system can also move laterally to place objects in the correct storage location.
AutoStore is a proven cube storage solution that has taken the market by storm as of late. It offers a simple, yet elegant solution to scalability that many solutions aren’t capable of matching. AutoStore is essentially a combination of 3 distinct parts: the grid, the ports, and the robots.
The grid is the frame of the AutoStore, which stores products in totes that stack on top of one another. The totes are then accessed by robots overhead, which can use an integrated pulley system to dig out totes one at a time, from the top down.
After the robots have acquired the donor tote, they will then proceed to a port and deposit a tote to a GTP station worker. While this is a simplistic view of the process, it gives a good idea of roughly how the system works.
The trend toward just-in-time production often requires sub-pallet level availability of production inputs. Making retrieval system ASRS a much faster way of organizing the storage of smaller items next to production lines.
The Material Handling Institute (MHI) is the nation’s largest material handling, logistics, and supply-chain association. Their definition of AS/RS is a variety of computer-controlled methods for automatically depositing and retrieving loads to and from defined storage locations. Amongst the AS/RS environment these technologies are found: Horizontal Carousels, Vertical Carousels, Vertical Lift Modules, and Robotic Storage and Retrieval Systems. Each technology has its unique set of benefits and disadvantages.
Advantages of ASRS
- ASRS technologies can deliver upwards of 400 donor totes to a single operator in an hour.
- Enables you to turnaround orders far quicker than standard methods of picking due to inherent rate increases, along with its ability to facilitate quicker movement throughout a facility.
- Proven to help retain labor by providing operators with an alternative to walking miles per day and allow for more comfort and efficiency at a workstation.
- Can significantly increase conventional storage when compared to standard methods.
Another AS/RS technology is known as shuttle technology. In this technology the horizontal movement is made by independent shuttles. They each operate on one level of the rack while a lift at a fixed position within the rack is responsible for the vertical movement. By using two separate machines for these two axes, the shuttle technology is cost effective for high-rate solutions.
These systems are used either as stand-alone units or in integrated workstations called pods or systems. They are usually integrated with various types of pick-to-light* systems and use either a light or LED on racks or shelves to indicate pick locations for basic usage or inventory management software.
These systems are ideal for increasing space utilization up to 90%, productivity levels by 90%, accuracy to 99.9%+ levels and throughput up to 750 lines per hour/per operator or more depending on the configuration of the system.
Mini load AS/RS share the same characteristics of a shuttle whereas they store product similarly, however, it is a single retrieval shuttle. While it decreases cost, it lowers the throughput rate at its expense.
*This technology is best used for split case order fulfillment. There are different types of Goods to Person (GTP) technology, but the principle is the same when an automated storage system delivers Stock Keeping Units (SKU) to a stationary pick station where the operator fills discrete orders.
RAFT is capable of having its robots maneuver horizontally and vertically, combining the density of AutoStore, with some of the benefits of a more traditional shuttle system. The result is a technology that densely stores pallets and brings them to any position on the exterior of the grid structure to be picked. RAFT’s pallet storage technique allows for an easy integration with conveyors and robotics, or with more traditional manual picks via an individual or fork truck.
Operate by placing products in configurable trays that are then stored on top of each other in a vertical cabinet. The trays are then brought to the GTP user at the workstation opening. An easy way to grasp VLMs is to think of them as giant vending machines capable of housing large amounts of product amongst a column of trays.