Choices, choices, choices—we are a society that demands options. But too many options can stall decision-making. You need time to look around, weigh your options (or look for alternatives!). Ordering a sandwich at the local deli is now an exercise in decision-making: What type of bread? Regular mayo or light mayo? Honey roasted or oven baked ham? Cheese? What kind of cheese? Even when the options are laid out in front of you in an orderly fashion, it can take time to look them all over and identify what you want.
While a variety of options may be what we want in our daily lives, it’s no help in a warehouse and distribution facility. The luxury of time to make a decision is not available to associates picking from inventory to fill orders.
Time spent at a picking destination—whether it’s a pick face, static shelving, pallet rack, or an automated storage and retrieval system (AS/RS) such as a horizontal or vertical carousel or a vertical lift module (VLM)—visually scanning the shelves or storage positions is time spent NOT picking. You can literally watch the minutes tick by as workers look for the correct item and match up part numbers to their paper pick lists. Here, the “No Soup for You” philosophy is best practice. You get to the front of the line, you order and you leave—no wasted decision-making time.
That’s where light-directed picking systems come into play. These systems utilize lights and/or alphanumeric display modules (sometimes sporting multiple colors) to direct the picker to an item’s location. The worker then spends no time making a decision; instead they simply follow the light as directed, pick the item and move on.
Pick to light technology can be integrated into virtually every kind of storage and picking system, both static and dynamic. They’ve been documented to deliver at least a 50% increase in pick rate productivity, and accuracy rates of 99% or more. Operators often report picking by light is like playing a video game—and much more fun than picking by paper—an added bonus!
There are several different types and styles available to match to different operations’ picking processes and storage systems. Here’s a brief overview of a few and how they can be used.
5 Pick to Light Technologies
1. Pick-to-Light/Put-to-Light/Batch Lights
Used with horizontal and vertical carousels, VLMs, static pick faces, shelving, or on mobile picking carts and cubby-hole based putwalls, these pick to light modules direct an operator to pick items from (or put items to) a specific location.
Pick to light units illuminate (and often blink) to indicate where the pick is stored, and often display the number of items required to pick; after the required action is complete, the operator presses a confirmation button on the module to confirm the pick (they can also indicate replenishment quantities and destinations). The same type of lights are known as put-to-light or batch lights when used for batch picking to totes or carts, and for picked item sortation and order consolidation at stationary workstations.
2. Transaction Information Center
Applied to vertical carousels and VLMs, this dynamic pick to light system displays discrete item identification in 1/10-inch increments. The module displays descriptions, quantities and other messages to help an operator select the correct item and amount for order fulfillment.
3. Light Pointer
Used with VLMs, this system deploys an LED or laser light mounted on a slider that moves horizontally on a guiding system within the access opening of the storage and retrieval unit. Software-driven, the pointer swivels to project its light beam into the storage tray and point to the location of the required item, eliminating search time in picking or replenishment.
4. Position Indicator Light Bar
Incorporated into the access openings of both VLMs and vertical carousels, these LED lights illuminate in alignment with the position of the required item where it is stored in the tray.
5. Light Tower
Integrated with horizontal carousels, this unit houses picking display modules in an upright (tower) configuration that aligns to the carousel’s stacked storage bins. The displays indicate the active carousel, shelf level, cell location and quantity to pick. Software-driven, a single light tower serves two horizontal carousels working together in a picking pod.
Pick to Light IRL:
Mazak implemented 13 Shuttle VLMs in its North American parts distribution center, all with pick to light technology to improve productivity by 80%