An automated storage and retrieval system (AS/RS)—also called AS-RS or ASRS—is a type or genre of warehouse automation technology specifically designed to buffer, store, and retrieve product and inventory on demand.
AS/RS technology varies substantially, and can consist of shuttles, cranes, carousels, vertical lift modules (VLMs), micro-loads, mini-loads, unit-loads, or other systems. It is often integrated with a warehouse execution software (WES), warehouse management software (WMS), or other controls.
Benefits of AS/RS
By automating the low-value and easily repeated task of inventory storage and retrieval, AS/RS brings many powerful benefits to the operations that utilize it, including:
- More efficient use of floor space
- Ability to reclaim unused vertical space
- Increased inventory storage density
- Improved ergonomics and safety, resulting in fewer accidents
- Increased throughput
- Reduced labor costs
- Fewer labor constraints due to labor shortages
- Often modular design for maximum flexibility
- Increased order picking accuracy
- Improved product security for premium inventory
Uses & Applications of AS/RS
1. Goods-to-Person for Order Picking and Packing
Picking, packing, and processing orders is one of the most time-consuming tasks in the order fulfillment process. In fact, the process of walking and manually picking orders can account for more than 50 percent of the time associated with picking. AS/RS offers an alternative to this through the use of Goods-to-Person (GTP, or G2P) order picking.
In a goods-to-person order picking system, the worker does not physically move from product location to product location to pick an order. Instead, a mini-load AS/RS crane, shuttle, AMR, carousel or VLM is able to retrieve the necessary stock from storage and delivery it directly to the worker, who operates in a pick/pack station. Once the appropriate amount of product has been picked, the stock is returned to storage and the next item needed for the order is delivered to the worker for picking.
This can be done on a full-case or split-case basis, depending on the operation. In either scenario, the AS/RS can sequence product so that it makes the most logistical sense—allowing cases of heavy product to be placed on the bottom of a pallet, for example, or organizing product so that similar products are together or in sequence to match a store’s layout, shipping zone, and cut-off time, to name just a few options.
2. Staging Orders for Shipping
The impact of e-commerce and omni-channel delivery on the order fulfillment process can not be overstated. Customers are now able to shop and place orders around the clock, and they want their product delivered fast and on time. But even if an operation accepts and processes orders 24/7, there are often constraints to shipping windows: Due to worker shifts, for example, or exorbitant night and weekend delivery fees.
To make up for these constraints, an operation can pick and process orders continuously and use an AS/RS to place them in a buffer storage to stage them until the shipping window is open. This saves time and allows an operation to continuously produce, even when orders can not physically leave the facility.
3. Managing Buffer Storage
In a typical warehouse, different processes take different amounts of time to complete. If these discrepancies are not properly managed, then all it takes is a poorly-timed piece of equipment or zone slowdown in any stage to bring an entire operation to a standstill or mass slowdown.
Buffering aims to prevent such a breakdown by ensuring that enough supplies/product are always on hand in different stages to keep an operation running. But while buffering makes sense, poorly managed it can become a logistical nightmare, requiring miles of conveyor to properly buffer and stage.
AS/RS has the potential to replace these conveyor buffering systems, allowing an operation to efficiently store buffer product and retrieve it as necessary. Depending on the specifics of the operation, this buffer management can be put in place in multiple areas of an operation’s workflow, whether that is staging product/raw material as it is delivered (“Inbound Receiving Buffer”) or storing inventory exactly where it will be needed along the production line (“Assembly Line Point-of-Use Buffering”) or (Order Consolidation) holding multiple portions of an order picked in different zones and then consolidating them for final packing and shipping.
4. Storage and Point of Use Storage
One of the primary benefits of AS/RS is its ability to store product in a way that makes the most efficient use of available space, especially over the long term. By implementing AS/RS, an operation can automate their long-term storage of raw material or product and retrieve what they need, when they need it.
By integrating the AS/RS with their Warehouse Execution Software (WES) it is also possible to intelligently utilize and optimize inventory via FIFO (First in First Out), LIFO (Last In First Out), lot numbers, expiration dates, order cut off times, packaging requirements and many organization and industry specific requirements.