As the warehousing and logistics industry accelerates its transition toward digitalization and intelligent operations, traditional warehouses are facing unprecedented pressure to upgrade. Rising labor costs, increasing order complexity, and increasingly stringent customer demands for fulfillment timeliness—these external pressures are forcing warehouse managers to reevaluate their operational models and seek practical paths for digital and intelligent transformation. Among the many available technical solutions, Electronic Shelf Labels (ESL) and Handheld Terminals (PDAs, also known as Portable Data Terminals) have emerged as the two most popular tools for warehouse digitization due to their flexible deployment, moderate implementation costs, and rapid return on investment. This article will systematically outline the specific application scenarios, core functional benefits, implementation strategies, and solutions to common issues for these two types of devices in smart warehouses, providing a practical reference guide for enterprises currently undertaking or planning to undertake warehouse digital transformation.

I. Electronic Price Tags and PDAs: The Two Core Tools for Warehouse Digital Transformation

Before delving into specific applications, we first need to clarify the roles and responsibilities of electronic price tags and PDAs within a warehouse digitization system.

An electronic price tag is an electronic display device installed on shelves that receives instructions from a back-end system via wireless communication technology to display product information, prices, inventory status, bin codes, and other details in real time. Its core value lies in upgrading static paper labels to dynamic information carriers that can be updated in real time, thereby enabling the digitization and visualization of bin information. Operators no longer need to memorize complex bin codes; they can quickly locate target merchandise simply by checking the label display, significantly reducing search time.

Figure 1: The Use of Electronic Price Tags in Modern Warehouses

A PDA (Portable Data Assistant) is a handheld mobile device that integrates functions such as barcode scanning, RFID reading, data communication, and photography. In warehouse operations, the PDA serves as a real-time interface between operators and the back-end system. Using a PDA, order pickers can scan barcodes to verify product information, view task instructions, report exceptions, and update inventory data in real time. The portability and multifunctional capabilities of PDAs provide robust technical support for mobile warehouse operations, making them indispensable devices for achieving “digitalization at the edge.”

II. The Core Value of Electronic Price Tags and PDAs in Warehouse Operations

2.1 Intelligent Storage Location Management

Traditional storage location management relies heavily on human memory and paper records, leading to widespread issues such as delayed updates to storage location information, difficulties for new employees in getting up to speed, and challenges in accurately tracking storage location utilization rates. With the introduction of electronic price tags, each storage location now has a “digital ID.” Information such as the location code, stored items, inventory quantity, and picking priority can be displayed in real time on the tag’s screen. The system can automatically adjust product placement based on sales data, placing high-turnover items in prime picking zones and moving slow-moving items to secondary areas, thereby achieving dynamic optimization of shelf space resources.

2.2 Significant Improvement in Picking Efficiency

Order picking is the most labor-intensive part of warehouse operations and a critical step in determining order fulfillment timeliness. Electronic price tags guide operators to designated storage locations and help them retrieve the specified quantities through flashing lights and digital displays, completely eliminating the need for manual searching and verification. Combined with the barcode scanning and confirmation function of PDAs, every picking action is recorded by the system, thoroughly eliminating the possibility of missed or incorrect picks. Practical data shows that after implementing electronic price tags to guide order picking, the time per item can be reduced by more than 50%, and the picking accuracy rate can reach over 99.9%.

2.3 Real-Time Synchronization of Inventory Data

Out-of-date and inaccurate inventory data is one of the biggest pain points in traditional warehouse management. After an order is shipped, delays or errors in manual data entry can cause significant discrepancies between book inventory and actual inventory, leading to a series of chain reactions such as overselling, stockouts, and duplicate purchases. The integration of electronic price tags and PDAs enables picking operations and inventory updates to occur simultaneously. Upon completion of every outbound, inbound, or transfer operation, data is uploaded in real time to the backend system, allowing managers to view the actual inventory status at any time and ensuring true “reconciliation of book and physical inventory.”

2.4 Full Traceability of the Entire Workflow

In a digitally transformed warehouse, every operation is accompanied by a complete data trail that includes a timestamp, the operator’s name, product information, and quantity records. Using this data, companies can reconstruct the complete picking path for any order, analyze operational bottlenecks, optimize staff scheduling, and establish a scientific performance evaluation system. For products with quality issues, it is also possible to quickly trace back to the specific stage in the process and the operator responsible, facilitating problem identification and the assignment of accountability.

III. Typical Application Scenarios for Electronic Price Tags and PDAs

3.1 Piece-by-Piece Picking in E-commerce Warehouses

E-commerce warehouses are characterized by a wide variety of SKUs, small quantities of items per order, long picking routes, and strict time constraints. In this scenario, the value of electronic price tags is particularly evident. Each SKU corresponds to an electronic price tag. Pickers follow the route assigned by the system to pick items in sequence; upon reaching each storage location, they can confirm the target item by the illuminated tag, eliminating the frustration of blindly searching through a vast number of SKUs. In this scenario, PDAs handle auxiliary tasks such as scanning for confirmation, reporting anomalies, and updating order statuses.

3.2 Expiration Date Management in Pharmaceutical Warehouses

The pharmaceutical industry has extremely strict requirements for managing product expiration dates, and the “first-in, first-out” (FIFO) principle for outbound shipments must be strictly enforced. Electronic price tags can display the expiration dates for each batch of goods. The system automatically places batches scheduled for imminent shipment in priority picking locations and adjusts the priority information displayed on the tags, thereby eliminating, from a technical standpoint, the risk of shipping expired products due to human error.

3.3 Managing Multiple Sizes of Apparel, Footwear, and Headwear

The number of SKUs for apparel, footwear, and headwear is enormous, and a single product typically comes in multiple color, size, and style variations, making management extremely complex. Electronic price tags display the specific product details corresponding to each storage bin, allowing pickers to complete their tasks accurately without having to repeatedly check labels or consult colleagues. PDAs can be used to scan product barcodes for secondary verification, ensuring that the items shipped match the customer’s order exactly.

3.4 Low-Temperature Operating Environment in the Fresh Produce Cold Chain

In low-temperature work environments such as fresh produce and cold chain operations, paper labels are prone to damage from moisture, handwritten information can become illegible, and operating a PDA’s touchscreen while wearing gloves is particularly difficult. Specialized industrial-grade electronic price tags feature a low-temperature protection design, enabling normal display and communication even in cold storage environments as low as -25 degrees Celsius. Low-temperature-rated PDAs are equipped with larger control buttons and a glove mode, ensuring efficient operation even in extreme conditions.

IV. Implementation Strategies for the Digital Transformation of Electronic Price Tags and PDAs

4.1 Phased Implementation: From Pilot Projects to Widespread Adoption

It is recommended that companies adopt a three-phase implementation strategy: “Pilot and Validation—Review and Optimization—Full-Scale Rollout.” In the first phase, select a core area within the warehouse (such as the picking zone with the highest average daily order volume) for a pilot to validate equipment performance, system stability, and staff adaptability, and to gain implementation experience. In the second phase, optimize and adjust the solution based on issues identified during the pilot, refining operational workflows and the training system. In the third phase, deploy the equipment throughout the entire warehouse while simultaneously advancing staff training and process changes. This phased implementation strategy can effectively control project risks and avoid the uncertainty associated with a one-time, large-scale investment.

4.2 Hardware Selection Must Be Suited to the Business Scenario

When selecting electronic price tags, key factors to consider include: screen size (whether images or QR codes need to be displayed), communication methods (2.4 GHz, LoRa, NB-IoT, etc.), battery life, protection rating (normal or low-temperature environments), and mounting methods (magnetic, screw-mounted, or snap-on). When selecting a PDA, key considerations include scanning capabilities (support for 1D barcodes, 2D barcodes, and RFID), protection rating, battery life, operating system (Android or Windows), and compatibility with existing systems. Avoid making decisions based solely on price or technical specifications; instead, conduct a comprehensive evaluation tailored to your actual business scenarios.

4.3 Focus on Deep Integration with the WMS System

Electronic price tags and PDAs are merely front-end execution tools; they receive their operating instructions from the back-end Warehouse Management System (WMS). If the data channel between the front-end devices and the WMS is not functioning properly, even the most advanced equipment cannot deliver its full value. During implementation, it is essential to clearly define the data interface specifications between the WMS and hardware devices, including order push mechanisms, order picking status feedback formats, exception handling procedures, and inventory synchronization rules. It is recommended to explicitly stipulate these interface specifications as an attachment to the contract at the signing stage to avoid project delays caused by integration issues later on.

Figure 4: Digital Workflow for Barcode Scanning and System Integration

4.4 Prioritize Training and Feedback for Frontline Staff

The successful implementation of new technologies ultimately depends on frontline operators. If training is inadequate, the user interface is poorly designed, or the user experience for frontline staff is poor, even the best technical solutions will struggle to deliver the expected results. Training content should cover basic equipment operation, troubleshooting common issues, safety precautions, and other relevant topics, and should include ample hands-on practice prior to deployment. After implementation, clear feedback channels should be established to promptly gather feedback on user experience and suggestions for improvement from frontline staff, enabling continuous optimization of operational workflows and equipment configurations.

V. Cost Analysis and Return on Investment Calculations

The unit price of electronic price tags typically ranges from 50 to 300 yuan, depending on the configuration. For a standard configuration supporting 3,000 storage locations, the hardware investment is approximately 200,000 to 600,000 yuan. The unit price of PDA devices ranges from 1,500 to 5,000 yuan, with significant variation depending on configuration and brand. If a warehouse needs to equip 20 PDAs, the equipment investment would be approximately 30,000 to 100,000 yuan. Fees for software system integration and implementation services typically range from 100,000 to 300,000 yuan.

The return on investment is primarily reflected in three areas: First, savings in labor costs. Once picking efficiency improves by 50% or more, the number of operators required to maintain the same production capacity can be reduced by 30% to 40%. Second, reduced losses from errors. When picking accuracy improves from 97% to 99.9%, direct and indirect losses caused by incorrect shipments, missed shipments, and customer complaint resolution can be significantly reduced. Third, improved management efficiency. Real-time data dashboards and order traceability capabilities significantly enhance the granularity and transparency of warehouse management, providing a data foundation for refined operations. Based on comprehensive calculations, a medium-scale retrofit project typically achieves a return on investment within 1 to 2 years.

VI. Frequently Asked Questions (FAQ)

Q: How often do the batteries in electronic price tags need to be replaced?

Answer: Electronic price tags typically use disposable or rechargeable lithium batteries, and their service life depends on the communication frequency and screen refresh rate. Generally, in scenarios with low-frequency updates, the battery can last 3 to 5 years; some models that support solar-assisted charging can further extend the battery life.

Q: Can a PDA be used in a low-temperature cold storage environment?

Answer: You need to use specialized industrial-grade PDAs designed for low temperatures. Standard commercial PDAs may experience issues such as screen malfunctions and battery degradation at temperatures below -10 degrees Celsius. Specialized low-temperature devices typically have an operating temperature range of -30 to 50 degrees Celsius and feature anti-fog and waterproof designs.

Q: How is the network stability of the electronic price tag system ensured?

Answer: Electronic shelf label systems typically use proprietary wireless communication protocols. When designing the network architecture, consideration should be given to signal coverage integrity and redundancy. Key nodes should be equipped with dual network ports or dual-link redundancy, and it is recommended that controller devices be configured with primary-standby redundancy to ensure that a single point of failure does not affect the overall system operation.

Q: How many PDAs does a warehouse need to be adequately equipped?

A: The number of PDAs deployed depends on the warehouse’s operational model, staff scheduling, and the volume of concurrent tasks. Generally, dedicated devices are assigned to fixed workstations (such as the receiving area and verification area), while pickers rotate the use of devices based on picking waves. Small- to medium-sized warehouses typically have 10 to 30 units, while large logistics centers may require more than 50. It is recommended to determine the number of units based on the actual peak number of concurrent tasks during operations.

Q: What should I do if a device malfunctions after the system goes live?

Answer: First, it is necessary to establish a rapid response mechanism for equipment failures, including channels for reporting malfunctions, procedures for replacing equipment with spares, and criteria for classifying failures. We recommend signing a maintenance contract with the equipment supplier that specifies response times and keeping spare equipment on hand in critical areas to ensure that normal operations can be restored within 4 to 8 hours after a failure occurs.

VII. Summary and Outlook

Electronic price tags and PDAs are the two most versatile and cost-effective core tools in the digital transformation of smart warehouses. Electronic price tags digitize and dynamically update bin location information, shifting the workflow from “people searching for goods” to “goods waiting for people”; PDAs enable real-time collection and transmission of operational data, replacing “rule-of-thumb decision-making” with “data-driven decision-making.” The synergistic application of these two tools provides a solid technological foundation for the digital and intelligent transformation of warehouses. For companies currently planning warehouse digital transformation, it is recommended to start by identifying business pain points, clearly defining core objectives and priorities, and selecting the technical solutions that best match their specific business scenarios. Throughout the transformation process, emphasis should be placed on pilot testing and continuous optimization, while respecting the operational habits and user experience of frontline staff. Digital transformation is not a one-time project, but rather a process of continuous iteration and deepening development. Selecting the right tools, establishing scientific management mechanisms, and cultivating digital operational capabilities are all indispensable.