Voice Picking Compared to RF Scanning For Warehouse Operations

Voice picking systems (or pick to voice) are used in only 20-25% of all warehouses and distribution centers, as the vast majority of warehouses rely on paper or mobile barcode scanning technology – commonly referred to as RF scanning systems – for order picking and other material handling tasks.

One of the most common questions asked by supply chain and IT executives when evaluating voice-directed picking is: How does voice picking compare to RF scanning?

This article answers that question by describing how voice directed processes differ from typical RF processes, and by highlighting the five main advantages of voice picking compared to RF in distribution center operations.

It should also be noted that many warehouses and distribution centers use order picking solutions that combine voice technology and RF scanning.

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These multi-modal order picking systems offer the best of all worlds. And multi-modal picking technology continues to evolve and incorporate new technologies, such as smart glasses for vision picking and augmented reality. (To see how voice compares to pick to light systems, read more here.)

What is RF Picking?

Surveys of supply chain professionals consistently indicate that more than half of all warehouses use paper to pick orders, and more than half also use RF scanning. (These percentages add up to more than 100% as many warehouses use different technology for different pick styles: piece picking, case picking, or full pallet picking).

RF (Radio Frequency) refers to warehouse operations systems in which workers access their work instructions on a wireless mobile computer (wearable, hand held, or vehicle mounted) that integrates with a host or warehouse management system (WMS) over a WiFi network (radio frequency, to borrow a term from the 1990s).

A typical RF scanning system provides text pick instructions on a computer screen. Pickers confirm their tasks by scanning barcodes on product or shelf locations, and by key entering information or pressing function keys on their mobile computer.

Many older RF systems use terminal emulation software (TE) running on the mobile computer. TE is a technology that translates applications and information that was originally designed for use on a desktop “terminal” to be used on a mobile computer.

TE is commonly used with older warehouse management systems and custom developed mainframe or host computer systems. (It is still common to hear warehouse operators refer to a mobile computer as an RF terminal, a nod to terminal emulation.)

RF Compared to Paper-Based Picking

Compared to paper-based picking, RF technology creates a consistent, system directed process with barcode scan confirmation of every location or product as items are picked or moved in the warehouse.

These RF systems eliminate paper-handling tasks (including tasks performed by clerical or supervisory personnel) and also reduce data entry steps outside of the main picking process.

For example, if an item is out of stock in the distribution center, that information will be written on a pick list and entered in a warehouse management system after the fact. RF processes using handheld or wearable computers improve picking accuracy, replenishment, and other hands-on warehouse and fulfillment processes.

It is not unheard of for a distribution center to suffer a decline in picking rates (lines picked per hour worked), when moving from paper to RF as part of a new WMS – assuming the basic picking process stays the same (for example, you do not create a batch picking process or implement a new zone picking approach).

A WMS-directed RF system adds data entry and barcode scanning steps that aren’t required in a paper-based process, which adds seconds to every pick transaction. These direct picking productivity losses are often most pronounced in piece picking, and among top performing order pickers.

Distribution center executives are sometimes willing to make this sacrifice in picking efficiency in light of other advantages of a new warehouse management system (real-time inventory visibility, improved accuracy, etc.). But growing numbers of warehouse operations and IT managers are turning to voice technology as an alternative to traditional WMS-directed RF order picking.

Voice Picking Compared to RF

In a typical voice-directed application (picking, receiving, replenishment, etc.), the worker wears a wireless headset that connects to a mobile computer. The voice of the system directs the user which location to go to and what to do and the user speaks into the headset microphone to confirm his work.

Voice recognition software on the mobile computer interprets the picker’s spoken responses. The majority of voice applications in use today operate as a warehouse execution system that integrates with a warehouse management system.

Voice picking offers greater flexibility compared to RF

The system gives operators greater flexibility to optimize the hands-on order picking process as their business changes. And many distribution centers can avoid a WMS upgrade by installing a voice-directed system alongside a legacy system.

In a voice directed picking application, when a picker arrives at the pick location ,they speak a check string to confirm they picking from the correct location.
The picker will also speaks the quantity of the item they grabs to verify the right number of items.
The checkstring can be a random series of digits printed on the picking location (or a pallet of goods in a location), or it can be part of a product id number (UPC, etc.) printed on the product package.
A well-designed pick to voice system also provides additional verbal instructions (put locations, units of measure, etc.) and voice activated help commands.
Modern voice and work execution systems allow workers to use speech and scanning interchangeably. (To see an examples of voice picking in use, access our online library of user videos.)

What Are the Benefits of Voice Picking?

Voice picking deliver significant improvements in productivity, accuracy and efficiency compared to RF and other technologies Take a look at the top benefits of voice:

Productivity – Voice picking saves an average of 2-3 seconds per pick compared to typical RF picking systems. (Read our guide to increasing order picking productivity)
Accuracy – With voice, pickers focus on products they are picking, rather than looking away at a device screen. Most DCs see greater than 99% accuracy rates. (Read our guide to increasing order picking accuracy)
Safety – Looking at an RF screen is inherently dangerous when traveling around a busy warehouse.
Training – New voice picking users can be trained in a few hours and hit performance goals in a week.
Worker Satisfaction – Workers prefer voice as it is easier to use and improves their job performance.

What Improvements Do DCs See Moving From RF to Voice Technology?

Warehouses and distribution centers that move from RF to voice technology typically see improvements in productivity, accuracy, associate training, worker safety, and employee satisfaction.

1) Two Hands Free Is More Productive

Voice users never have to juggle a scanner while trying to grab and move items, so they can grab, lift and move items more efficiently, saving time in every pick and move. In addition, voice users never have to stop to scan or key enter a quantity or exception – they speak and listen as they move.

2) Heads-Up Improves Accuracy and Safety

With voice, users never have to look down at a terminal screen to get information – their eyes stay focused on the work they are doing. Every time a user looks away from a pick location there is a possibility he will pick the wrong item. And like texting and driving, using an RF terminal while driving a piece of equipment is never a good idea.

3) Ease of Use and Training

Throughout our lives we learn to do tasks via verbal instruction, so voice picking is inherently relatable and easy to learn. Most voice users can be working on their own on their first day of training, and the majority reach initial performance standards within a week or two.

4) Worker Satisfaction

When moving from RF to voice, associates typically see significant improvements in accuracy, productivity, and safety, which translate into higher levels of job satisfaction and sometimes increases in pay. Many also report less job-related stress.

Combining Voice and Other Mobile Technologies Is the Key to Double-Digit Productivity and Accuracy Improvements

Needless to say, the benefits of any technology in a given warehouse will depend on how well the technology is used in a given process.

Voice technology alone may not result in double-digit productivity gains in every scenario, which is why it is important to consider ways in which voice and other mobile technology (scanning, smartglasses, RFID, etc.) can each be incorporated as a component of a process improvement project.

Our whitepaper, Three Paths to Picking Productivity with Voice and Warehouse Optimization, underscores this point and discusses how different approaches to implementing voice technology can lead to far different results.

If you’d like to learn more about how you can combine voice, scanning and visual prompts in one optimized workflow, schedule a call with one of our warehouse experts.