Choosing the Right Picking Technology for Your Operation

A comparison of light-directed, voice-directed and wireless picking systems

By Greg Chaffee, Vice President of DirectPick™, Diamond Phoenix

In the ever expanding market for order fulfillment technologies that deliver improved performance, higher accuracy, and greater return on investment, several technologies have emerged as practical options and are being implemented much more frequently. Light-directed, voice-directed and wireless picking systems are all technologies available today. But how do you know which one is right for your facility?

Wireless Picking
In a wireless picking system (also called RF systems), operators use handheld wireless devices that direct them in the picking process. A pick list generated by the host computer is downloaded to the device. The operator is directed to a location, where he scans the location/item bar code to verify that he’s at the correct place. The device then tells the operator to pick a specific quantity of items. When the pick is complete, the operator enters the number of items picked into the device for verification purposes.

Wireless picking systems have the lowest entry fee of the three technologies described here. In addition, the system is very accurate; companies that implement a wireless picking system will realize significant improvement over manual systems, with an increase in accuracy up to 99%. Wireless systems are also very portable and can be easily expanded to accommodate for changes in volume.

However, there are several considerations that must be taken into account before selecting a wireless system. When compared to light-directed or voice-directed systems, wireless systems are not quite as easy to use; the operator’s hands are not completely free for picking, as he must hold onto a scanner throughout the picking process. Training may also be more difficult, as it takes time for operators to become proficient at operating the scanner and following its instructions.

Finally, scanners may run into difficulty if bar code labels are not a standard size, if labels are dirty, or if lighting in the picking area is poor. Access points must also be properly planned; any objects blocking the access point may cause “dead zones” within the building and if too many operators are connected to an access point, productivity will decrease due to system delays.

Light-Directed Picking
Light-directed picking systems (also called pick to light) use small lights mounted on a rail to direct the operator. When an order is downloaded from the host computer, the lights associated with any items in the order will light up. The operator moves to a lighted location, where he will see a number on the display indicating how many items to pick. When the appropriate quantity has been picked, the operator presses the button to indicate that the order is complete before moving on to the next light.

Depending upon the system purchased, light-directed picking systems can be very flexible, even allowing for re-configuration of the system “on the fly.” In addition, it’s very easy to learn and use, which is ideal for companies with a high turnover rate.

In a dense environment, light-directed picking of high moving SKUs is faster than picking by voice because all the lights associated with an order will light up at one time. The picker already sees the picks ahead of him without having to follow the serial script of voice picking; he is effectively multi-tasking by planning his upcoming picks while making the current pick.

However, as with any technology, there are a few things to keep in mind when considering a light-directed picking system. It is important that products are slotted appropriately to take advantage of picking rates; otherwise, efficiency targets may not be achieved. In addition, productivity will be affected by other activities that occur during the picking process. For example, if items must be labeled and packaged as they are picked, this may cause productivity rates to decline.

Pick to light is best used in high speed picking operations such as in the retail, pharmaceutical, cosmetics, and electronics industries. Because pick to light systems eliminate the reading, writing, and searching required by paper-based or wireless systems, picking time may be cut in half and accuracy may be improved up to 80%.

Voice-Directed Picking
Rather than using visual cues, voice-directed picking relies on audio cues to tell the operator what and how many to pick. The system is very easy for workers to learn; they listen and speak to the system as naturally as they talk to each other. Speech recognition and synthesis translate data from a host computer into spoken directions for the user. The system then translates the user’s spoken responses back into data for the host. Operators do not read screens, displays or printouts; the voice activated system keeps their hands and eyes free, allowing them to fulfill orders quickly and efficiently.

The operator simply wears a headset with a microphone to interact with the computer and a small, battery-powered computer is worn on the belt. After signing in and training the computer on her voice, the user listens for the location of the item. When the user arrives at that location, she confirms that she’s in the correct area by speaking the location code into the microphone. The computer then tells her the quantity to pick; when finished, she speaks again, verifying that she picked the appropriate quantity. When the pick is complete, the user speaks one last time to indicate that the task is complete. The computer then directs her to another location and the entire process is repeated.

Voice-directed picking is a straightforward, flexible system that allows you to manage picking assignments and product selections, monitor the selection process in real time, track and manage reported shorts as they occur, reprioritize activities and manage emergency orders or behind-schedule deliveries, measure productivity of individual selectors and selector teams, enable multiple-order “batch” selection, and run “dynamic zones” in operations with pick and pass selection.

Companies that employ voice technology in their operations experience many benefits:

• An increase in productivity up to 35%
• Errors are reduced up to 80%
• Accuracy is improved up to 99.99%
• Payback is typically achieved within 16 months
• Return on investment is improved by 150%

Voice-directed picking has been utilized in a variety of industries, including pharmaceuticals, retail, direct to consumer, entertainment/music, consumer products, chain drug stores, industrial parts/manufacturing, automotive, and grocery. Any distribution environment where full case and broken case picking are required, and where “hands busy tasks” (e.g., data entry) or “eyes busy tasks” (e.g., looking at a part while entering data) are used are potential candidates.

Within these environments, voice-directed picking can be applied in several areas, including logistics (order filling, cycle counting, put away), inventory management (product tracking, shipping/receiving), manufacturing (quality inspection, finished goods inspection, scrap reporting/defect tracking), and returns processing (reverse logistics, remanufacturing operations, product identification).

Each of these picking systems has its benefits and drawbacks and one solution will not work in all situations. Therefore, it’s important to understand the differences between light-directed, voice-directed and wireless picking systems and how each may benefit your operation.