How to Choose the Right Light Directed Picking System for Your Warehouse: A Complete Buying Guide

What Is a Light Directed Picking System?

A light directed picking system, often called a pick-to-light system, uses illuminated alphanumeric displays mounted on rack shelves, flow racks, or cartons to guide warehouse operators to the correct pick location and quantity. By eliminating paper pick lists and reducing search time, these systems significantly boost picking accuracy (typically 99.9%+) and throughput in high-volume, item-level order fulfillment environments. This guide provides an objective, data-driven approach to evaluating and selecting the right system for your operation.

Core Components to Evaluate

Before comparing specific product models, understand the main hardware and software elements that make up a modern light directed picking system:

• Pick Display Modules: Each display unit is assigned to a storage location. The module shows the pick quantity and optionally the order number or SKU. Look for display types: LED numeric (1-4 digits), OLED (for dynamic text), or full graphic LCD.
• Confirmation Buttons: Operators press a button (usually capacitive touch or mechanical) to confirm the pick. Some systems include a built-in barcode scanner on the module for additional verification.
• Zone Controllers: A single controller can manage 16 to 128 display modules per zone. The controller communicates with the host warehouse management system (WMS) via Ethernet, RS-485, or wireless protocols.
• Power Supply: Typical input 24V DC or Power over Ethernet (PoE). Low voltage systems reduce electrical hazard risk in wet or dusty environments.
• Software Middleware: The interface layer that translates order data from your WMS into pick instructions for the displays. Look for standardized API support (REST, XML, or SOAP) for easier integration.

Key Technical Specifications Comparison

The table below compares typical parameters across three common categories of light directed picking systems. Use these figures as baseline criteria when requesting quotations from suppliers.

Important Selection Factors Beyond Specifications

Integration Complexity

Not all WMS platforms support light directed picking natively. Check whether your existing WMS has a certified connector, or if the system provider offers a standard middleware interface. Ask for a list of compatible WMS versions (e.g., SAP EWM, Oracle WMS, Manhattan Associates, Blue Yonder). Integration effort can range from 2 days (out-of-the-box API) to 4 weeks (custom development).

Environmental Considerations

If your facility operates in cold storage (freezer down to -25°C / -13°F) or in areas with high humidity, make sure the displays are rated for those conditions. Standard LED units often fail below 0°C due to LCD freezing issues; choose OLED versions with wide temperature range or heated lenses for freezer applications.

Scalability and Future Expansion

Determine the maximum number of pick faces your system can support. Many controllers can be daisy-chained, but latency increases beyond 200 modules per chain. For facilities planning to grow from 500 to 2,000 pick faces, opt for a system that uses distributed controllers with Gigabit Ethernet backbones.

Ergonomics and Operator Training

The physical size of the display, viewing angle, and brightness affect operator comfort. Look for modules with adjustable brightness levels (100–1500 lux) and wide viewing angles (>120°). Systems that support color-coded zones (e.g., red for urgent, green for normal) reduce cognitive load. Typical training time for a new operator on a light directed system is under 30 minutes.

Total Cost of Ownership Analysis

When budgeting, include not only hardware and installation but also:

• Initial Integration Fee: $5,000–$15,000 depending on complexity
• Annual Software License / Support: $2,000–$8,000 per year (if not bundled)
• Spare Modules and Cables: Recommend 5% spare parts stock
• Power and Network Infrastructure: PoE switches or 24V power supplies – quote separately
• Maintenance: Electro-mechanical button systems may need button replacement after 500,000 actuations; capacitive touch modules have no moving parts but may require firmware updates

Checklist for Requesting Proposals

Use the following list when comparing supplier quotes:

1. Number of pick faces and zones required.
2. Maximum picks per hour expected per zone.
3. Existing WMS version and database type.
4. Environmental conditions (temperature, humidity, dust).
5. Power source availability (PoE or dedicated 24V).
6. Preferred confirmation method (button, scanner, RFID).
7. Required display information (quantity only, or SKU + order number).
8. Warranty period and mean time between failure (MTBF) specifications.
9. On-site installation and training support hours included.
10. Future expansion capability (maximum modules without changing controller).

Final Recommendation Process

Start by conducting a pilot test with 50–100 pick faces using two or three shortlisted suppliers. Measure actual picking accuracy, throughput, and error rates over 2–4 weeks. Involve your picking operators in the evaluation because their acceptance directly impacts ROI. Most providers offer a demo kit or rental program for a modest fee. Remember that the cheapest upfront cost may lead to higher integration and maintenance expenses over the system’s typical 5–7 year lifespan.

By carefully evaluating the technical parameters, integration requirements, and total cost elements outlined above, you can confidently choose a light directed picking system that maximizes your warehouse productivity and accuracy for years to come.