Put-to-Light is a highly productive goods to person order fulfillment solution for high volume operations with a large number of SKUs — such as retailers or wholesalers that have store replenishment or e-commerce fulfillment needs. A highly accurate and cost effective order fulfillment methodology, put-to-light increases throughput rates by directing operators to efficiently sort batch picked items to specific put locations such as totes or bins that are associated with unique orders.

In doing so, the put-to-light process enables a single pass batch pick of the SKUs needed to fulfill multiple orders, while speeding the sortation process and dramatically decreasing operator errors though light directed technology.

Put-to-light (also known as put-by-light) is also well-suited to receiving operations in which small items are received in mixed containers (case or pallet).  In these situations, operators can be directed to consolidate individual items as they are scanned into receiving for batch delivery to common warehouse locations, aisles, or storage media. This dramatically reduces walking for the put-away process.

Put-to-Light in Receiving Area

Put-to-Light being used for receiving goods into a distribution center.

How Put-to-Light Technology Works:

Put-to-Light PQD

Pick quantity displays (PQDs) are used to direct puts via lights and item quantity displays.

Like a Pick-to-Light system, Put-to-Light systems utilize Put Quantity Displays (or PQDs) to direct operators in the order fulfillment process. A PQD is a bright, easy to read, LED display panel that is used to direct a put (the placement of a product) to a particular shelf, tote, or bin that has been associated with a unique order, warehouse location, or store location.

While there are a wide range of Put Quantity Displays available, they usually consist of:

  • An indicator light (used to draw a picker’s attention to the location).
  • One or more numeric and/or alphanumeric displays (used to indicate the quantity of items to be picked from that location — and an SKU #, if needed).
  • One or more push buttons (used to confirm task completion).
  • Up/down push buttons (used for incrementing/decrementing the quantity, if necessary).
  • Illuminated arrows to indicate exact product location (if that PQD is shared between two pick locations).

Optional Put Quantity Display/Pick-to-Light system features can include:

  • Audio alerts (for pick confirmation as well as hand held radio frequency device integration).

The Put-to-Light Process:

The put-to-light process (or put-by-light process) begins when Invata’s FastTrak® warehouse control system software optimizes open orders for batch picking from bulk storage. An algorithmic analysis groups open orders according to the proximity of SKUs needed to fill those orders and then creates a single pass, batch pick for those items via the shortest routes through the warehouse.

put-to-light batch pick to cart

The put-to-light process often begins with items being batch picked from storage.

Put-to-Light put wall

A put wall is used in a shipping department to direct an operator to sort items to specific cartons associated with unique orders.

The items required to fill the selected orders are then batch picked into containers or onto carts and then delivered to the put-to-light system. Once the batch pick items are in the put-to-light sorting area, an operator begins the put (or batch pick sortation) process by selecting items from the container and scanning them.

As each item is scanned, the Invata put-to-light system triggers the Put Quantity Displays to illuminate in every put location that requires that item in order to complete an order. The PQDs also indicate how many of each item is required as well.

Operators allocate the items to their appropriate put locations and confirm that each task is complete by depressing an illuminated push button. When a put location has all of the items needed to complete an order, the put-to-light PQD indicates that the order is complete and ready for the next stage of processing such as packing or shipping. Confirmed put results are updated on a real time basis for updates to the host ERP via Invata’s warehouse software.

put-to-light put to container

Put-to-light can also be used to sort to containers for larger quantity orders.


Enhanced Productivity through Put-to-Light:

Ideally suited for retail and wholesaler fulfillment as well as receiving operations, Invata put-to-light systems are both cost efficient and easy to learn. Order selector training on a put-to-light system is usually requires just a few minutes, allowing the use of temporary labor to meet seasonal demand. And with light based systems both the productivity of the order processors is dramatically improved, while the error rates are dramatically decreased compared to results obtained in either paper based or radio frequency order fulfillment methods.

Benefits of an Invata Put-to-Light solution:

  • Highly accurate and productive batch picking and order sortation solution.
  • Eliminates the need for paper pack lists and RF terminal handling.
    Frees operator hands for efficient product handling.
  • Minimal operator training is needed, making the system quick and easy to use.
  • Dramatically improves productivity and order fulfillment accuracy, substantially decreasing counting and substitution errors.
  • Supports an unlimited number of SKUs, since PQDs are only needed for put locations versus item storage locations.
    Easily scalable with addition of more put stations at any time.
  • Enables tracking of the productivity and accuracy of individual operators.
  • Enables proactive throughput management via real-time work-load balancing in Invata’s FastTrak warehouse software.
  • Put Quantity Displays include built-in diagnostics features for use in system diagnostics.
  • System is fully integrated with Invata WCS for host interface and management, as well as real-time decision execution.
  • Includes fully integrated error correction and exceptions processing capabilities.
  • Costs less than pick-to-light system, as fewer displays are required.

Put-to-Light Integration Considerations

put-to-light wall

In put walls, each location can represent a unique order or store location.

Of equal importance to the performance of a put-to-light system is the warehouse management system (WMS) and warehouse control system (WCS) software used to integrate a put-to-light into an intralogistics system.

Invata’s own FastTrak® WM+ warehouse software suite is a key asset to achieving optimal performance for put-to-light systems of all types.

To learn more about what an Invata put-to-light solution can do for your operation, contact us. We’ll be happy to share more about our rich history of employing put-to-light technology to enhance order fulfillment productivity.

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