Pick to Light
Overview
Pick-to-Light uses light devices mounted at item locations on flow rack, shelving, workstations or other storage media to guide operators to the correct product locations and quantities required to fill an order. Also commonly called pick-by-light or light-directed picking, in the right application Pick-to-Light systems increase pick rate productivity and order accuracy by reducing the walking and reading associated with paper-based or even other semi-automated picking approaches.
The key to Pick-to-Light is its simplicity. Operators scan a bar code license plate on a tote or shipping container to launch an order in their zone. Illuminated LEDs direct pickers to the right product location, and display the required unit quantity. After picking all pieces the operator confirms the completed activity, often by pressing a button on the device. They then proceed to the next illuminated location and repeat the process until all the necessary picks in their area are finished.
Pick-to-Light is often applied to Zone Picking, where each picker works in a designated zone to reduce their walk time. Once all the picks for an order are completed in one zone, the order is passed to the next one that also contains items needed. This team-based, assembly line style approach keeps everybody in the pick line building orders.
Solution Components
Like many paperless picking solutions, Pick-to-Light installations feature both hardware and software components.
Hardware
There are multiple Pick-to-Light system suppliers, many with unique hardware products offerings and preferred platforms. Almost all Pick-to-Light hardware products include the following system components:
- Light Device. This is the primary interface between the picking system and the operator. Most light devices offer an LED to locate the product SKU, and a Quantity Display presenting required units. There is usually a Confirmation Button of some type allowing pickers to verify completed tasks. The device may also feature additional buttons enabling pickers to increment/decrement the displayed quantity to communicate short picks, over picks or other specially programmed functions. Many suppliers offer their own unique light module product where there’s options for available quantity digits, locator LEDs that are also the confirm button, different form factors, sizes and colors.
- Alphanumeric Bay Displays. These multi-digit/character displays are often positioned at each bay of rack or pick zone. They communicate order numbers, handling directions (“Pass to Zone 3”), completed orders, other special instructions.
- Installation Materials. Today most leading PTL suppliers offer a bus or duct-based light device mounting system. This technology was developed to combat the installation and maintenance costs and complexity of the previous generation’s serial cable based systems. The new ‘track light’ product design mounts to existing rack or other storage media, reducing installation time and costs. The light devices are fed power and data independently of one another, creating many advantages. A malfunctioning light doesn’t necessitate extenuated repair downtime for the whole line. The ‘plug and play’ like installation allows devices to easily be addressed and added as needed for system expansion. Lights are easily repositioned on the duct for convenient SKU re-slotting. Overall bus-based based light technology enables users to apply Pick-to-Light with more scalability, flexibility and self sufficiency. Installation materials usually consist of some type of duct, power supplies and controllers to mount, provide electricity and communicate with the system.
Software
Each Pick-to-Light provider likewise offers their own unique software product to configure and manage the light-directed pick process. Some users opt for standalone systems but in most high volume applications a solid interface between the PTL software and the users’ ERP, SCM, SCE, WMS or other major host system is required for seamless integration to directly download order file data.
Personal computers have provided flexibility, a user friendly interface and lower costs to broaden the size and scope of Pick-to-Light applications. From smaller pilot systems to large, multi-site deployments, today’s more advanced PTL software products have developed into sophisticated order fulfillment execution systems. Many include tools that expand or contract work zones to efficiently adjust labor to current order volume. Often reporting is available to provide insight on work in progress, work completed, pick rate productivity and other vital statistics.
Applications
The versatility of Pick-to-Light offers itself to many effective applications including order picking, parts picking, sortation, kitting, consolidation and assembly. PTL works best when applied to operations where a relatively small number of SKUs (approx. 20%) account for a high percentage of daily order volume (approx.80%). Classic Pick-to-Light in a Zone Picking approach is best when these higher velocity SKUs are grouped together in a moderately dense space, so walk time reduction is most effective. However there are interesting Pick-to-Light configurations that can effectively automate medium and low velocity pick areas too and achieve strong benefits. Some operations are fulfilling full case quantities using Pick-to-Light in case pick to belt applications.
Most leading Pick-to-Light products can also integrate with other automated systems such as A-Frames, carousels, RF and Voice picking allowing users to apply the best toolset to different areas and tasks unique to their operation. Also an increasing number or discrete manufacturers are adopting Pick-to-Light to error-proof a variety of assembly tasks and add quality on their end of the supply chain.
Pick-to-Light has been adopted by a wide spectrum of vertical industries including:
- Retail
- Direct Selling
- eCommerce & Catalog
- Pharmaceutical
- Medical Products
- Automotive
- Health & Beauty, Cosmetics
- Liquor Distribution
- Grocery and Convenience Store
- Third Party Fulfillment Providers
- Computers, Electronics, Cell Phones & Accessories
- Music/Video/Software Fulfillment
- Manufacturing
Advantages
Many Pick-to-Light users gain speed, order accuracy and cost efficiency to their order picking process, full project ROI is often achieved quickly. Some of these benefits include:
- 30-50% increases in Pick rate Productivity
- 99.9+% accuracy rates
- Shorter Order Cycle Times
- Increased Throughput
- Reduced Employee Training Time
- Improved Customer Service
- Lower operational costs through reduced labor, errors, rework or chargebacks
- Predictable Picking Process
- Reduced Costs through the elimination of paper picking lists
- An intelligent pick process with visibility into daily performance
