An ASRS (Automated Storage and Retrieval System) is the technology infrastructure that lets a warehouse or distribution center store and retrieve pallets, cases, and containers with no direct human involvement. Instead of operators driving forklifts through aisles of racking, an ASRS uses stacker cranes, shuttle robots, or shuttle carts that move automatically inside the rack, guided by WCS software that receives orders from the WMS. The payoff: higher storage density, faster operations, lower error rates, and reduced labor costs over the long term.
Core components of an ASRS system
A complete ASRS has four layers. The first is the storage layer: high-density racking engineered to bear the handling equipment and to maximize the available height of the warehouse. The second is the handling layer: the stacker cranes (cranes that travel within the aisle) or the shuttle robots (shuttles that operate inside the rack channel). The third is the transport layer: the chain, roller, or belt conveyors that connect the storage zone with the workstations. The fourth is the software layer: the WMS manages inventory and orders, while the WCS turns those orders into commands for the physical equipment.
Types of ASRS: stacker crane, shuttle, and mini-load
The unit-load stacker crane operates in aisles and handles full pallets of up to 1,500 kg at heights of up to 40 meters. It is the best fit for high-bay warehouses with high pallet-movement volumes. The mini-load stacker crane handles containers, cases, and totes in narrower aisles: ideal for intensive picking in e-commerce, pharmaceuticals, or manufacturing. The shuttle system (pallet shuttle or tote shuttle) uses autonomous robots that operate inside the rack channel, delivering maximum storage density with a smaller footprint. The VLM (Vertical Lift Module) is an alternative for workshops and spare-parts warehouses: it takes advantage of clear height without needing an aisle, with goods-to-person deliveries in under 15 seconds.
How a stacker crane works, step by step
The process starts in the ERP or sales system: when an outbound order is generated, the WMS receives and processes it. The WMS sends the retrieval mission to the WCS, which calculates the product's location, the availability of the nearest stacker crane, and the optimal route. The stacker crane travels to the correct position within the rack, extracts the pallet or container with its telescopic fork, and carries it to the outbound station. The full cycle-from order to delivery at the station-takes between 45 and 120 seconds, depending on storage height and depth. Every movement is logged in real time in the WMS, updating inventory with no manual intervention.
When it makes sense to install an ASRS in your warehouse
An ASRS is justified when at least three of these conditions are met: the warehouse handles more than 500 movements per day; available floor space is limited but there is clear height to exploit; labor costs are significant or staff turnover is high; picking or inventory errors create operational or reputational impact; and operating volume is high enough to amortize the investment within 18 to 36 months. In Argentina, Decree 513/2025 (0% tariff on ASRS equipment) and the RIMI regime (accelerated depreciation of capital goods) significantly improve the projected ROI.
First step: a free technical consultation
An ASRS is not just technology-it is a strategic decision that shapes a warehouse's layout, processes, and operating model for decades. Before making any investment decision, the STOKA team runs a free technical assessment: throughput analysis, SKU profiling, and a 10-year ROI simulation for your specific warehouse or distribution center. The first consultation carries no cost and no obligation.
Frequently asked questions
What is the difference between ASRS and warehouse automation?
Warehouse automation is the broad concept: it includes ASRS, AMR robots, conveyors, automated picking systems, and WMS/WCS software. The ASRS is the automated storage and retrieval portion, which can be the core of a fully automated warehouse or a targeted technology for a specific zone.
How long does it take to install an ASRS?
A complete ASRS installation project runs from 5 to 10 months, from purchase order to operational go-live: 2-3 months of detailed engineering, 3-4 months of manufacturing, and 4-10 weeks of installation, integration, and commissioning at the warehouse.
Does an ASRS require changes to the warehouse structure?
It depends on the design. If the warehouse has enough clear height and a level floor slab, the ASRS can be installed without major construction. Projects that require more height do call for building a new facility or expanding vertically. STOKA assesses technical feasibility on site before submitting a proposal.
What happens if the ASRS stops due to a fault?
Modern ASRS systems have redundancy in their control equipment and manual emergency operating modes. If a stacker crane fails, the aisle can be operated manually with a forklift in emergency mode. The MTBF (mean time between failures) of DELIE stacker cranes exceeds 8,000 hours of continuous operation.