Automated storage and Retrieval Systems enable businesses involved in order fulfilment and warehousing operations to automate their material and inventory handling functions. But there is never a one size fits all. The ASRS solutions available in the market can handle different types, volumes and velocities of inventory at variable speeds to ensure varying throughput demand for efficient material handling.
It can be broadly divided on the following basis:
- Load based
- Bot based
- Carousel based
Load based Automated storage and retrieval system
Unit-Load AS/RS are larger systems that typically store pallet loads. The system can take loads as large as 2500 Kgs and place them on pallets or within a container of that size, to handle odd shaped goods. In a crane-based unit load ASRS, it features one or more narrow aisles of storage rack structures specially designed for pallet racking. The structure can reach up to the height of 30 meters which is more than enough for a typical warehouse. The storage and retrieval machine (SRM) travels between the racking in two dimensions, instructed by software which dictates where and how items are placed in a particular location. Usually, the system contains one SRM per aisle. But in a high throughput system, multiple SRMs can be dedicated to single aisle and in case it is a slower system, one SRM can be allocated to multiple aisles.
Miniload ASRS are smaller systems that store items in totes, trays or cartons which typically weighs less than 50kgs. Similar to unit loader, miniload ASRS are generally composed of two aisles of narrow racking structure, between which an SRM moves in two dimensions. One of the main benefits of mini-load ASRS is its modularity. The height of the system can range from 8-12 meters, depending upon the requirement and space available.
Micro-load stocker ASRS
Micro-load ASRS are self-contained structures which store products densely into bins, stored and retrieved by an extractor and deliver the item to the operator at a pick face. The pick face of a micro-load stocker often uses a conveyor to bring a queue of items. There are different systems of micro-load stockers available in the market and each model performs the storage and retrieval operation in a distinct way. Micro-load stockers are typically integrated with other ASRS system, which serves to the buffer and stage items which reduce the need for conveyors in the warehouse and eventually increase the available floor space. It is especially suited for industries where picking and kitting operation requires fast throughput.
Bot-based Automated storage and retrieval system
Shuttle based ASRS
Shuttle based ASRS technology is suitable for both FIFO and LIFO configurations and deep-lane or shallow-lane storage structures. There are many kinds of shuttle based systems available in the market depending upon the shape, load, size etc and the nature of inventory. In this system, SRM is a shuttle or small robot. When an item is requested, it moves from the workstation to the racking where the items are stored. It retrieves the item and travels back to the workstation. In other systems, manual labor plus conveyors are used to move items from racking to the workstations.
For warehouses with low ceilings or other space restrictions for example cold storage, this type of ASRS solutions is the most suitable choice.
Floor Robots ASRS
Why go to the storage area when the storage area can come to you. Floor robots are self-mobile ASRS solution, store inventory on a portable storage shelving structure. This structure is retrieved and transported an area where the operator needs it and are moved across the facility by using AMRs. The structure returns to its allocated space once the operator selects the required item. The solution is suitable for slow to medium moving inventory. The solution is scalable as the operation can be easily expandable by increasing the number of AMRs into the system. The standard weight capacity for this solution is 500kgs per shelving system.
Carousel based Automated storage and retrieval system
The vertical carousel comprised of a series of carriers attached to a chain, which travels in a vertical loop around a track like a Ferris wheel. This solution is suitable for slow to medium moving inventory. On the command of the operator, the items are safely and quickly delivered to the ergonomically positioned workstation. Manufacturers introduce new additions to the solution, but the main concept of the technology remains the same.
The solution can be made scalable with the addition of light or voice-based picking technology that enables picking of multiple orders simultaneously. It typically offers the capacity of 750kg per carrier, the vertical carousel is a cost-effective and reliable solution.
Horizontal carousel is a highly dense storage structure where the bins are mounted on an oval track which rotates horizontally to perform storage and retrieval function. The solution is designed to store slow and medium moving inventory and can handle items and cases weighing up to 100kg. The structure is often installed in groups called pods to generate maximum speed and achieve maximum throughput. The solution can be made scalable with the addition of light or voice-based picking technology that enables picking of multiple orders simultaneously. This structure is also equipped with an automated door system which creates an enclosed solution. Overall, the system allows excellent space utilization and high storage density.
Vertical lift module ASRS
Although designed primarily for storing and retrieving slow to medium-moving products, VLMs (Vertical Lift Modules) are important components on the system side of supply chain flow. It is one of the best solutions for the facilities where the ceiling height goes up to 100 feet and have heavy items that require lifting assistance for the operator to handle them safely.
VLM consists of two columns of trays, parallelly facing each other and a mechanical extractor between them like the elevator. The mechanical extractor travels up and down between the columns automatically retrieving and storing the items from these trays stored on the columns. In warehouses, inventory is stored in these columns and by entering the tray number on the built-in control pad, the extractor triggers and retrieves the items from the columns by intelligently detecting the location of that item. This operation is applicable for extraction as well as replenishment of material inside the vertical storage module.
Hence, ASRSs can be relatively small but they are one of the most important subsets of equipment within a larger warehouse environment. ASRS systems can provide great value in all sectors but have special significance in Food & Beverages, Consumer Goods, Pharma, Dairy, Cold Store, and Metals. These systems can serve as the primary means of storing and retrieving product in the system. Depending on the system, AS/RSs can handle loads consisting of small parts or large, or multi-ton units.