Canadian Grocer Blog Entry: May 10, 2013 (here)
The emergence of goods to person (GTP) automation technology for high volume distribution centers presents some exciting opportunities for Grocery distributors. These technologies are designed to automatically store and retrieve merchandise within a dedicated zone in the distribution center. This effectively eliminates putaway and replenishment work and also significantly improves the productivity for order selection. The technology choices vary as does the range of suppliers. This discussion provides a basic primer for an interesting application called Autostore.
Is Your Company a Candidate for Goods to Person Automation?
Historically, distribution automation technology has been focused on automating the movement of full and partial pallet unit loads. Today we now have proven solutions to automate full case distribution centers as well as semi-automated split case distribution operations. To my knowledge we still do not have solutions that fully automate the process of order selecting split case merchandise but I know that they are diligently working on this.
Most goods to person systems are designed to semi-automate the distribution of split case merchandise meaning that the customer is ordering less than a full case. Having said this, there are some GTP solutions that also have the flexibility to handle both split and full case merchandise within the size limitations that the system can support. Due to the fact that GTP technology requires a relatively high up-front capital investment, we believe that the following operational characteristics need to be in place in order to consider this technology:
- A minimum of 5,000 order lines per shift to be processed from the GTP system.
- A minimum of 2 outbound shipping shifts per day
- Split case merchandise that can fit within a standard tote / tray (i.e. product dimensions need to be within reason).
- Merchandise weight per tote/tray needs to be reasonable such that the entity being handled does not exceed specified system weight constraints (typically in the range 80 - 100 pounds)
- The system ROI is improved as fully loaded warehouse wage rates increase hence companies that have high cost warehouse labor are ideal candidates.
- Again the system ROI is improved where there are serious warehouse space constraints and/or the cost of warehouse space is high.
This is a solution that was originally developed in Norway in the 1990's. It has since been implemented in Europe at about 20 companies and has recently arrived in North America. We believe that this technology is ideally suited for companies that need to distribute a high number of slow moving split case SKUs that are small enough to fit into a 15.75"W x 23.6"D x 12.2"H tote. Companies that have invested in this solution include manufacturers and distributors of electronics, components, fasteners, industrial supplies, apparel, and medical supplies. Within the Grocery industry, ASDA (owned by Walmart) acquired a massive system in 2012 for their Leicester, UK depot. This system consists of 70,000 storage bins, 12 goods-to-man picking ports and 160 robots.
The system is basically one big dense cube of storage made up of adjacent vertical stacks that are columns of 16 bins high. Each bin can store one or multiple SKUs subdivided within the bin. The size and shape of the grid can be adapted to any existing facility and can work around existing building columns. To store and retrieve the bins, a set of battery-powered robots move horizontally along a rail grid that resides on the top surface of the self-supporting storage system. Each robot is equipped with 8 wheels so that 4 are used when traveling along the X axis and the other 4 are used when traveling along the Y axis. The mobile robots themselves are not that big - they have similar dimensions to the bins being stored. Each robot is equipped with an extended hoist apparatus that vertically lifts bins from within each vertical stack to the top of the grid. The robot itself stays on the aluminum grid rails at the top of the modular storage cube. The robot's hoist has a set of 4 steel bands that descend into the vertical stack to "grab" the topmost bin within the stack. The robots essentially dig into the columns to get the tote that is needed for a picking assignment. Once the tote is retrieved, it is lowered down a vertical shaft to the picking work station.
Order selectors work at ergonomically designed pick stations that can be designed to support the picking of one or multiple orders concurrently. Bins can be presented to the operators at varying rates of between 250 to 1200 per hour. The selector picks from the bin and then puts to the set of orders being picked which is governed by put to light technology. Completed orders are usually pushed off to a conveyor for transference to packing/staging/loading.
Key benefits include:
- High storage density up to 16' in height
- Eliminates travel time for storage, replenishment and picking functions
- Highest levels of efficiency and accuracy
- Flexibility to expand system to handle higher throughput volume
- Ability to deploy in existing buildings
- No single point of failure - easy to deploy spare robots.
- For a highly detailed and unbiased overview of this application you can click here for more information.
A more in depth and unbiased review of the Autostore system can be found here.
Marc Wulfraat is the President of MWPVL International Inc. He can be reached by clicking here. MWPVL International provides supply chain / logistics network strategy consulting services. Our services include: supply chain network strategy; distribution center design; material handling and automation design; supply chain technology consulting; product sourcing; 3PL Outsourcing; and purchasing; transportation consulting; and operational assessments.