Automation: Picking the Right Techniques and Technology

Mar 14, 2007 9:29 PM  By

Today’s warehouse managers face a number of challenges. Customers demand perfect order accuracy; smaller and more-frequent orders cover a greater number of SKUs; senior management calls for lower costs and increased productivity.

With these persistent demands, warehouse managers remain caught in the middle. For those managers operating without the benefit of automation, the picking and packing functions remain two of the most labor-intensive and costly jobs in the operation. When performed manually, picking and packing can be a major source of errors, expense, and decreased efficiency.

If that’s the case in your warehouse, an automated order fulfillment system may help you take your picking and packing operation to the next level.

Take a snapshot of your warehouse
To start evaluating your warehouse for picking or packing automation, you need an accurate picture of your order profiles and volumes. Automating an operation based on inaccurate data is a recipe for disaster.

At the same time, be sure to investigate alternative techniques. Should you pick to order or cluster-pick to multiple orders? Perhaps a “put” concept — where products for a number of orders are bulk-picked and then distributed to individual orders — has merit.

In some situations, a combination of techniques is warranted. At the initial stages of your planning, it is important to focus on techniques and not technologies. Deciding on the right techniques will guide you in determining the right technologies to use.

Turn to an expert
After this step, the logical process is to evaluate your warehouse layout itself. Is your layout conducive to the intended order-picking technique, and if so, is it optimal for high-productivity material handling? For an expert opinion on this question, it is probably best to turn to a material handling consultant or a systems integrator.

A material handling engineer or specialist will analyze your slotting–where your product is stored, how it’s stored, and its volumes and speeds–in order to gather information on how well your warehouse is laid out. This process normally begins with an ABC analysis, which will determine the items that move the fastest (A products), those that are intermediate movers (B items), and items that are the slowest (C products).

Once an expert performs his analysis, your warehouse may require a reconfiguration to optimize product storage prior to picking and, ultimately, to packing. You may also need to rearrange your storage infrastructure, including racking and shelving. The process of reconfiguring your locations is commonly called reslotting.

The goal of these reconfigurations is to optimize the picking and packing processes as much as possible so that they make sense within the physical constraints of your warehouse space and workforce. Ask yourself whether poor slotting causes your workers to walk too far, bend too much, or otherwise work inefficiently or inaccurately to complete their tasks. Does your warehouse layout or storage equipment yield the same negative results?

Consider all your options
Before reconfiguring your existing layout or equipment, you should begin to envision what role, if any, you want automation to play. Entirely manual picking and packing might require one layout or storage arrangement, but partially or fully automated systems would likely require a different arrangement.

A material handling expert can offer invaluable advice when it comes to making these decisions. Do you need conveyors? Is light- or voice-directed picking or putting needed? Is a sophisticated warehouse management or control system in order?

A site analysis and risk assessment could help you determine whether automated picking or packing would improve productivity and accuracy to the extent that you would see a return on your investment. It is possible that your warehouse could benefit enough simply from a layout and slotting reconfiguration. In this situation, automation technology may not be advantageous.

The decision to automate
Automation could be the right solution for you. In that case, your next step is to determine which level of automation your warehouse needs.

The first step in transitioning from a completely manual system to an automated one involves moving to radio frequency-based (RF) wireless data technology supported by RF mobile computers and hand scanners. But even though RF-based picking and packing will dramatically improve accuracy, RF systems bring a learning curve for the workers who have to operate the equipment and may require extra training. .

The results of the ABC analysis will assist in evaluating which technology, if any, suits your warehouse. Depending on your order volume, medium- and fast-moving items could be candidates for a pick-to-light implementation and possibly a put-to-light system for replenishment of picked items. The pick- and put-to-light methods use light and number displays mounted on or near the shelves or the racks to tell operators what they need to pick or put, replacing the paper orders of a manual system. Light-directed picking and putting can increase productivity by as much as 50% from a paper-system baseline.

Extending a pick- or put-to-light system beyond the medium- and fast-moving items may also make sense. You might decide to implement light technology in your whole warehouse — densely for fast movers and less densely as you move down to the slow-moving items. Alternatively, RF-directed carts can be added to a pick-to-light system for cluster-picking slower-moving line items in a large product range.

Voice-directed picking is another option, particularly where RF-based mobile picking hardware is already in place. With voice-directed systems, computer-generated voice commands give pickers their instructions. Voice-picking is particularly suited for slower-moving items and for facilities where longer walks between picking areas are required.

Voice devices can also complement light-based systems. Light- and voice-automated systems free pickers from having to carry around their paper pick instructions and can dramatically improve accuracy and productivity.

The final step
These types of automation technologies require the underlying software to support them, and you may be required to upgrade your software to a system that improves your order fulfillment. Today’s warehouse-specific systems are built to manage picking and packing as well as to optimize system throughput through order and wave planning. Basic order fulfillment software that is required to use automation may provide additional productivity and functionality.

These systems also work with your underlying material handling equipment, such as conveyors, picking carts, sorters, and automatic storage and retrieval systems, so that your warehouse work and material flows are totally integrated. For instance, your software system might direct pickers using pick-to-light or pick-to-voice, making sure that when they’re ready to pack a box, a conveyor routes a box to them and then is ready to move it to the next packer, if necessary.

The two most important reasons to automate are productivity and accuracy. If automation means two pickers can pick what three pickers used to do in a manual system, you have increased your picking productivity 50%. Also, if automation means orders are now close to 100% accurate, then you’re helping to ensure that many more customers are satisfied and that you’re incurring lower order costs because your new system makes fewer mistakes.

You will also receive more supervisory and overall system information in an automated, software-directed system. Whereas a picker in a manual, paper-based system can certainly pick what’s on his paper order, his supervisor won’t know where he is in the process or when he’s finished until he brings that paper back for another order.

In an automated system using light or voice devices, the picker must respond to computer prompts at all times so that his actions are integrated into the software’s reporting functions. The software not only optimizes the picker’s productivity but also gives his supervisor the ability to see his status in real time and to adjust to conditions such as stock-outs.

When order volumes push the limits of your warehouse’s productivity and accuracy, it’s time to consider picking and packing automation. That’s also the time to partner with an experienced material handling consultant or integrator who will help you determine if automation can help you improve your warehouse operation at a sufficient return.

Bill Hubacek is director, distribution technologies, FKI Logistex North America, a provider of integrated material handling solutions.

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