Storage & Retrieval
Sometimes working the cube is the best thing to do to increase storage utilization and improve picking efficiencies. Automated storage and retrieval systems (ASRS) create dense inventory storage to maximize floor space by using the vertical space in a building. These systems can increase picking labor productivity by eliminating lost time walking and searching for inventory, and drive +99.99% accuracy rates by presenting the right inventory at the right time.
The inventory stored in ASRS systems will vary by solution, often categorized into three types of solutions.
This operation stores work in-progress or completed orders until they are needed. This type of solution can allow operations to work ahead of order commitment dates and even peaks and valleys in labor requirements. The orders stored in the buffer and retrieved and delivered at the time they are needed for shipping.
This operation stores completed orders or work in process, retrieving containers in the order they are needed. A common application for completed orders is reverse truck stop loading. In this case, orders are flowed to shipping so that the truck is loaded with orders for its last stop first, and the first stop last.
This operation stores items, typically slow- to medium-movers, retrieving them to present them to an operator. This is typically the most complicated of the solutions, requiring a high level of coordination between overall operations and the ASRS system to optimize the solution so inventory and orders flow efficiently through a building.
Successful automated storage system solutions include thinking and planning beyond the storage mechanisms. Timing and coordination of the subsystem with the overall order fulfillment processes and building flow, how items are inducted and stored, types of containers whether they be cases, totes or trays will be loaded and handled, among other things need to be considered.
An ASRS solution can include one or more of the following technologies:
Mobile Robotic Goods-to-Operator
Robotic goods-to-operator uses autonomous mobile robots to create a storage and retrieval picking subsystem that includes put-away, inventory storage, replenishment and order picking. The solution is very flexible in how it adapts to changing inventory profiles and order volumes. The modular system architecture of this approach can scale to increase storage volume or fulfillment throughput independently by adding more storage racks or robots, as needed. The subsystem works by tracking inventory stored in racks, and bring the racks required to fulfill an order to an operator station. The operator performs a pick from racks as they are presented, and consolidates items required for an order.
High Density Cube Storage
The i-collector is a three-dimensional dynamic storage system used as a buffer device for a wide range of standard totes and trays. The storage structure stores totes, a stack of totes or trays from one side, and then retrieves what is needed from the other. The design allows induction and takeaway through a manual process or automated flow. The design is based on proven technology, and its size can easily be adjusted to fit existing building. Applications include item picking, case picking, shipping buffers, and production buffers.
Mini-Load & Shuttle Systems
Mini-load and shuttle systems are used in ambient, chilled or frozen environments to solve similar applications. Mini-load tends to fit with low to medium throughput solutions, while shuttles fit better with medium to high performance solutions. These systems create extremely high storage density and can handle a broad range of items; working well in in e-commerce, omnichannel, and wholesale fulfillment solutions.
The main difference is how the system interacts with storage. Mini-load systems use a single load handler mounted on a moving mast to access all the locations in a storage aisle, while shuttle systems use more load handler vehicles that are assigned to specific levels of the storage structure. They have some variation in specifications like maximum product weights, aisle lengths, or storage depth, but the main tradeoff between the systems are operational throughput vs. investment.
The design of ASRS subsystems need to consider performance of each of its elements like the pick and drop off flow, lift throughput, vehicle/load handler performance as well as type and spread of inventory. Oftentimes the most challenging aspects of ASRS systems are the overall solutions flow and external error prevention. Spending the time and effort to work through the solution flows and how subsystems interact is a critical part of implementing a successful solution.