Light directed picking PQD

Pick Quantity Displays (or PQDs) are used to direct operators in the order fulfillment process: A colored light draws an operator’s attention to a location, while a numeric display indicates the quantity of an item needed to complete an order.

A key component of Invata’s FastTrak warehouse control system is its real time management of light directed picking operations.

Light directed picking covers an array of light-enabled processes including those found in pick-to-light, put-to-light, and pack-to-light systems as well as material handling processes that use computer work station screens or reader boards to enhance accuracy and productivity.

A highly accurate and cost effective processing methodology, light directed picking relies on real time access to data to maximize throughput, accuracy, and productivity. Access to real time data is achieved through Invata’s FastTrak warehouse execution software and warehouse control system software which dynamically manages all aspects of light directed picking systems, including:

  • directing all picks, puts, and packs
  • tracking inventory items
  • optimizing system and resource utilization efficiency
  • monitoring productivity
  • updating WMS or Host ERP systems

Working in conjunction with our FastTrak database, which is uniquely engineered to process data points in the milliseconds required to ensure information is immediately available for real time decision execution, our FastTrak WCS optimizes light directed picking systems in a variety of applications.

Light Directed Picking Applications


Receiving operations can utilize FastTrak WCS light directed processing to receive incoming goods to inventory. For operations in which items are received in mixed containers, for example, put walls or put-to-light (also known as put-by-light) systems can be used to direct operators to consolidate individual items for batch delivery to common warehouse locations, aisles, or storage media.

Light Directed Receiving - put-by-light

A put-by-light process in a receiving operation directs an operator to a put wall in which totes represent various warehouse aisles or zones.

Integrated with tethered, wireless, or radio frequency scanners, FastTrak directed put-by-light systems scan every item entering the warehouse, confirming receipts by SKU and item count, while processing exceptions for missing or unanticipated items. Data exchange with the host ERP enables receipts to flow into the building, minimizing touches, without paper. This type of light directed receiving process dramatically reduces the amount of walking and searching required to stock a facility while streamlining the receiving process.

Person to Goods Picking

light directed picking - pick-by-light

Pick-by-light displays draw a picker’s attention to the goods to be picked and indicate the quantity to be picked for a particular order.

Order fulfillment operations can utilize FastTrak’s WES light directed picking functions to manage person to goods pick-to-light (also known as pick-by-light) systems. Shown to be one of the most productive order fulfillment solutions for high volume, full and split case fulfillment operations, Invata pick-by-light systems dramatically improve productivity while decreasing counting and substitution errors by enabling hands free picking.

Functions include pick-to-tote and pick-to-carton as well as single order picking and batch picking. Pick-by-light displays can be configured to indicate each, pack, and case quantities and can display lot numbers, if needed. FastTrak WCS also allows pick line zone boundaries to be fixed or floating (for use in bucket brigades) to enable maximum operator productivity as well as staffing flexibility.

Goods to person Picking

Order fulfillment operations can also utilize FastTrak’s WCS light directed picking functions to manage goods to person pack-to-light (aka pack-by-light) systems.

In a goods to person pick environment, inventory to be used in order fulfillment is delivered via manual processes or conveyed from an automated storage and retrieval system to order processing work stations where light displays direct pick and pack operations.

light directed picking

A workstation computer screen directs an operator to place an item in a particular tote associated with a specific location.

Ideally suited for distribution operations with retail store allocation and replenishment requirements, FastTrak’s WCS directed pack-by-light is a highly accurate and cost effective, hybrid put-by-light fulfillment process in which full cases can be efficiently broken down to store ready quantities and packed for individual store locations.

Pack-by-light systems are also a key component of ASRS based goods to person stations and often incorporate spotlight indicators for identifying items to be picked as well as scanners and scales to verify items and quantities. These goods to person workstations yield high levels accuracy and productivity, while providing superior ergonomics and working comfort for system operators.


light directed picking - put-wall

Put wall used in pack-by-light operation.

For omni-channel fulfillment operations that can benefit from an optimized batch picking process in which all goods needed to fulfill a group of orders are collected in a single pass through the warehouse, light directed put-by-light systems — used in conjunction with batch picking processes — offer a highly accurate and productive order fulfillment solution.

In these environments, Invata’s FastTrak warehouse control system software optimizes open orders for batch picking and then directs the put-to-light sortation needed to complete the fulfillment process for each individual order.

FastTrak WCS light directed functions manage all aspects of the put process, allocating inventory to orders and to put wall locations in ways that maximize operator productivity and put location availability.


Shipping operations can utilize FastTrak WCS light directed processing to assemble multiple parts of an order that must come together from disparate work areas. Light assisted equipment, tightly coupled to RF technology can combine disparate parts into a single shipping container.

In these environments, reader boards are often employed to let operators know which order is being processed, where and how the goods for that order should be consolidated (e.g. container or pallet), and how many pieces will be required to complete the order. Special messages such as packing or loading instructions can be displayed, if needed as well.

light directed picking - paperless pallet building

Reader boards direct final order staging for paperless pallet building shipping stations, conveying information such as order number for each shipping lane, number of cases expected, and number of cases remaining to complete order.

Light Directed Picking Integration Considerations

Nearly all light assisted picking systems require some level of integration with other warehouse automation systems including:

  • An ERP or WMS system for the purposes of receipt verification, inventory adjustment, and order allocation.
  • The material handling system for the routing and sorting of goods.
  • An ASRS for the delivery and sequencing of inventory to be used in order fulfillment.

As part of a light directed system Invata’s WCS can be used on a stand alone basis with legacy WMS and ERP systems or as part of a fully integrated Invata WMS/WCS with a uniform interface to a host ERP.

In situations where client’s are using legacy software systems, FastTrak’s bi-directional interfaces enable Invata clients to use our software to fill gaps in functionality between existing systems and light directed picking systems. This allows our clients to leverage existing resources, avoiding costly modifications to existing WMS and ERP system resources (and the subsequent support issues that often accompany them), and utilize FastTrak’s unique integration capabilities as a glue that binds new and legacy systems in one integrated operation.

Light Directed Picking Integration Experience

Invata’s light directed picking systems controlled by our FastTrak WCS warehouse software are being utilized at dozens of client facilities in a number of countries. A partial list of the successful implementations and the host (WMS and ERP) interfaces include:

  • SAP
  • JD Edwards
  • MS Dynamics
  • Manhattan
  • Red Prairie
  • IRMS
  • HighJump
  • Oracle
  • Retek
  • Infor
  • TecSys
  • And many others as well as legacy client systems
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