Strengthening your supply chain one link at a time.
Traditionally, manual picking required warehouse teammates to roam the warehouse to pick inventory from any location and deliver the product to the packing area. A goods-to-person (GTP) solution is an automated order fulfillment method that uses material handling equipment (MHE), such as robots, shuttles, cranes or other automated devices, to retrieve and deliver products to picking teammates resulting in increased efficiency and productivity. Selecting the best GTP solution is critical to satisfy specific warehouse environments and needs such as the size of your warehouse, type of inventory, order volume, and budget. The different types of GTP solutions include:
Automated Storage and Retrieval Systems (ASRS) combine storage racks, shelves, and robotic shuttles to retrieve inventory from designated storage locations and deliver them to a picking station. The teammate picks the appropriate SKUs from the shuttle tote and places them in a shipping container or box. Then the tote is delivered back to storage. The process continues until the order is complete.
An ASRS delivers high productivity rates and provides high storage density, but they can be expensive to install and maintain. Unit-Load systems handle heavy full or partial pallets and cases, typically stored in narrow aisle pallet racking locations. Unit-Load solutions can handle loads up to 5,500 lbs. The narrow aisle racks are paired with a crane which is used to easily store and retrieve the pallets. Mini-Load solutions handle totes, trays, and cartons. If you lack floor space and require storage locations for a large amount of stock keeping units (SKUs), then a mini-load solution may be effective.
Shuttle systems use bots or shuttles that travel on tracks between a racking structure to deliver inventory from designated storage locations. Shuttle systems are best for clients seeking speed and efficiency.
For autonomous mobile robot (AMR) solutions, the AMR travels up to a storage rack location to retrieve inventory and then travels down to the floor to deliver inventory to the picking workstation.
A carousel solution, horizontal or vertical, consists of bins of inventory that continuously rotate to provide the appropriate bin to pick inventory. Since many clients are beginning to take advantage of their vertical space, Vertical Lift Modules (VLMs) are great for smaller warehouses with limited space. VLMs use an elevator-like mechanism and trays to deliver inventory to a designated picking station. The best way to describe a VLM is to think about a giant vending machine filled with containers using an inserter/extractor to locate, retrieve, and deliver inventory on a tray to the teammate. VLMs utilize the full ceiling height. VLMs are not suitable for larger operations with high volumes.
Mobile Rack/Pallet-based solutions use a grid of rack storage locations. Inventory is retrieved by an AGV or AMR that travels underneath the rack to deliver the rack to a pre-assigned picker workstation. With this, multiple SKUs are presented to the teammate which increases order picking efficiency. This solution is best for clients seeking flexibility and scalability.
The benefits of implementing a GTP solution include the following:
To automate the GTP process, a warehouse execution system (WES) and/or warehouse control system (WCS) can offer full control over different types of equipment and machinery such as:
The WES/WCS interact with the warehouse management system (WMS) and equipment in real-time. For example, the WES/WCS receives instructions from the WMS that must be executed by material handling equipment (e.g. shuttle, conveyor). The diagram below shows a GTP shuttle order pick solution diverting the order to the packing area via a conveyor. Please see the high-level swim lane diagram below:
Note: In the diagram above, process boxes that include “Teammate” could occur in either the WMS or WES/WCS depending on how the software is deployed.
In conclusion, a GTP solution revolutionizes the order fulfillment process by integrating with robots to deliver inventory directly to workstations. Investing in a GTP solution can provide efficient distribution, reduce unproductive walking time, and foster a safer work environment. With many warehouse automation methods available, an experienced professional can help select the best-fit solution for your fulfillment or distribution operations.
—Ashley Rhodes, St. Onge Company
