What is Put-to-Light?

3 minute read

Pick-by-light and put-to-light are light-directed order fulfillment technologies that increase the speed and accuracy of picking putting, sorting, or kitting items in a warehouse, distribution center or manufacturing facility.  Light modules are installed on racks, shelves, bins, or totes.  When a pick-list is initiated, a light indicates how many of each item should be picked from (pick-to-light) or placed in (put-to-light) a specific location.

Pick-by-Light vs Put-to-Light

Pick-by-light and put-to-light are similar processes that use the same hardware and software.  In a pick-by-light scenario, the light indicates how many items should be picked from a specific location. 

Conversely, in a put-to-light scenario, the light indicates where the already-picked item should be placed.  Put-lights are often used on picking carts, bins, totes, put-walls and other sortation equipment.  These systems are sometimes referred to as "scan and sort". 




Common Ways to Use Put-to-Light


Batch-Picking with Put-to-Light Technology

In this scenario, a picker will pick the items for multiple orders in one pass through the warehouse.  There are many ways to batch-pick with put-to-light technology, but let's examine two common batch-picking scenarios that use put-to-light.

Batch Picking to individual orders

In this scenario, the picker places the just-picked item into the appropriate tote, bin or box as directed by the put-to-light hardware.  Typically, each tote, bin or box contains one order.  When the pick-list is complete, the orders can be passed off to the packing or shipping department.

Batch picking with delayed sortation

In this delayed sortation, the picker has already picked the items on the picklist.  A barcode scan causes the put-light, installed on a put-wall or sortation rack, indicate the location where each picked-item should be placed.  

In both scenarios, a picking cart is used to pick inventory and an automated system increases picking accuracy and errors by indicating where the picked-item should be placed.  

There are other ways to use put-to-light systems.  Learn more with the 2018 Buyer's Guide to Put-to-Light, which covers types of systems, advantages, costs, technology updates, and more.


Pack to Light or Put-to-Store

Pack-to-light or put-to-store is a specific type of light-directed putting operation to optimize retail store replenishment.  Often full-case quantities are broken down into "eaches" and a specific quantity sent to each retail location.

Pack-to-light optimizes flow-through sortation processes.  For example, in a pack-to-light or put-to-store scenario, a case of product arrives via conveyer belt. The operator will scan the case (or a picklist, depending on your operation), causing the put-lights to illuminate indicating the item and quantity to be "put" or "packed" in that location. These items are shipped to the retail store.   


Manufacturing and Kitting

Put-to-light is also used in manufacturing and kitting applications.  Kitting is a process in which related items are packaged together as a single unit.  Kitting reduces part and component assembly time and leads to greater order fulfillment efficiency within the supply chain.


What's new in Put-to-Light Technology?

Put-to-light technology has not changed much in 35 years - until now.  Voodoo Robotics has leveraged the internet-of-things and created wireless Cloud Display Devices that can be used in all sorts of ways - including put-to-light.  

A simple URL, like the one in your web browser, causes the associated device to light up with two lines of custom text - in almost any language.  Self-monitored devices run on two AA batteries can last for years, depending on usage.  It's simple to integrate with your WMS/ERP or you can even use it with Google Sheets or Excel!