Unlocking Advanced Inventory Control in Warehouse with License Plate Numbers (LPNs)

In today's world of modern warehouse management, precise inventory tracking and management are absolutely vital. As supply chains become more complex and customer expectations rise, businesses require robust systems to ensure efficiency, accuracy, and real-time visibility. License Plate Numbers (LPNs) have emerged as a fundamental component in achieving these goals.

LPNs are unique identifiers assigned to units within the warehouse, such as pallets, cases, or individual items. They facilitate detailed tracking throughout various warehouse processes. Beyond basic identification, advanced LPN capabilities enable sophisticated inventory management strategies, such as FIFO (First-In, First-Out) tracking, item-level tracking, nested storage tracking, etc.

This comprehensive guide delves into the technical aspects of LPNs and the correlation between LPNs and critical warehouse processes.

What Are License Plate Numbers (LPNs)?

An LPN is a unique alphanumeric identifier assigned to a specific grouping of inventory within a warehouse. This grouping can range from a single item to a pallet containing multiple cases. LPNs serve as a shorthand reference that encapsulates essential information about the inventory, including:

• SKU details
• Batch or lot numbers
• Expiration dates
• Quantity
• Current location within the warehouse
• Status (e.g., available, reserved, in transit)

By scanning an LPN, warehouse personnel can instantly access all relevant data about the inventory without manual lookups, enhancing speed and accuracy in operations.

LPNs in Warehouse Operations

LPNs integrate seamlessly into various warehouse processes, playing a pivotal role in inbound operations, internal movements, outbound processes, returns, and inventory audits.

Inbound Operations: Receiving and Putaway

Implicit LPN Generation at Receiving

Implicit LPN generation refers to the automatic creation of LPNs by the WMS during the receiving process. As goods arrive at the warehouse, the system assigns LPNs to incoming units (pallets, cases, items) based on predefined rules and logic.

Automation Benefits
Efficiency: Eliminates manual data entry, reducing processing time.
Accuracy: Minimizes human errors associated with manual LPN assignment.
Consistency: Ensures uniform tracking of all inbound goods.

Enabling FIFO and Expiry-Based Management
With implicit LPNs capturing the receipt timestamp and expiration dates, the WMS can enforce FIFO and FEFO (First-Expired, First-Out) methodologies.

FIFO Tracking:
- Prioritizes dispatching older inventory first.
- Reduces the risk of obsolescence.

FEFO Tracking:
- Essential for perishable goods.
- Ensures products are shipped before reaching their expiration dates.

Internal Inventory Movements: Transfers and Consolidation

LPN Nesting

LPN nesting refers to the ability of a WMS to track relationships between different levels of inventory. For instance, a pallet may contain multiple cases, and each case may contain multiple individual items. By using nested LPNs, a warehouse can manage and track the inventory at each level of storage from the individual item all the way up to the pallet.

In a nested LPN structure, each storage unit is assigned its own LPN, and these LPNs are linked together hierarchically. This allows the system to maintain visibility into not only the overall contents of a pallet but also the specific details of what’s inside each case on that pallet.

LPN nesting is especially useful in industries where products are stored in multi-level packaging units. Some examples include:

• Apparel: Individual shirts packed into cases, and cases stacked on pallets
• Electronics: Devices like phones packed into boxes, then onto pallets
• Pharmaceuticals: Medicine bottles packed into cases, cases stacked onto a single pallet for distribution

LPN Nesting in the WMS

• LPNs for Individual Items: At the lowest level, each individual item (e.g., a bottle of medicine) can be assigned its own LPN. This LPN contains all relevant information about the item’s SKU, batch number, and expiration date.

• LPNs for Cases: A case containing multiple items (e.g., 24 bottles) is then assigned its own LPN. This case-level LPN is "nested" under the item-level LPNs, allowing the system to track both the contents of the case and its movement as a whole.

• LPNs for Pallets: Finally, the cases are stacked onto a pallet, which receives its own LPN. This pallet LPN is nested above the case-level LPNs, meaning the system can track not only the pallet’s movement but also the contents of each case and item within it.

Outbound Operations: Picking, Packing, and Shipping

In outbound operations, LPNs enhance the efficiency of picking, packing, and shipping by offering a structured approach to identifying and moving items.

• LPNs for Order Picking:
  • During the warehouse picking process, workers can scan LPNs to confirm that the correct pallet, case, or individual item is selected. This minimizes the chances of human error, especially in high-volume warehouses where orders consist of multiple SKUs.

• LPN Consolidation:
  • As orders are packed, multiple LPNs (from cases or individual items) can be consolidated into a new LPN, representing the final shipment. This ensures the entire order is traceable under one unified LPN, simplifying the shipping process.

• Integration with Shipping Labels:
  • LPNs can also be integrated with shipping labels and logistics providers’ tracking systems. When the outbound shipment leaves the warehouse, the LPN can be tied to the carrier's tracking number, enabling visibility from the warehouse to the customer’s doorstep.

Returns and Reverse Logistics

LPNs also play an important role in returns management, ensuring that returned items are efficiently reintegrated into warehouse inventory or sent to appropriate locations for disposal or refurbishment.

• Processing Returns with LPNs:some text
  • When returned goods arrive at the warehouse, LPNs can be assigned to track them through the inspection process. If the items are to be restocked, their original LPNs can be reused, or new LPNs can be generated if they are consolidated into new storage units.

• Disposition and Refurbishment:some text
  • For items that require refurbishment, repair, or recycling, LPNs allow the warehouse to track their movement through various stages of the returns process. This ensures that defective goods are properly accounted for, reducing potential errors and losses.

LPN capabilities in a WMS

Advanced WMS platforms offer capabilities to manage LPN lifecycle to enhance operational efficiency and flexibility. These features address common challenges in warehouse environments and provide more robust control over inventory.

Configurable LPN Logic

In some cases, the logic for generating and managing LPNs is highly configurable. For example, businesses can set up custom rules to define how LPNs are assigned based on the type of goods being received, their storage location, or the type of packaging.

• Example: A warehouse handling both perishable and non-perishable goods may configure the system to automatically generate LPNs with expiry date tracking for perishable items, while non-perishable goods may only require SKU and quantity information in their LPNs.

LPN Consolidation and Splitting

LPN consolidation and splitting allow for even greater flexibility when managing inventory. These functions let operators merge multiple LPNs into a single LPN (consolidation) or divide a single LPN into multiple smaller LPNs (splitting) as inventory is reorganized or orders are fulfilled.

• Consolidation Example: When picking items for a large outbound order, cases from different locations can be consolidated onto a single pallet and assigned a new, consolidated LPN. This reduces complexity during shipment and makes it easier to track inventory at the pallet level.

• Splitting Example: If a customer order only requires a partial shipment from a pallet or case, the system can automatically split the original LPN into smaller LPNs, allowing for precise tracking of remaining stock.

Multi-Warehouse LPN Management

For businesses that manage inventory across multiple locations or warehouses, the ability to track LPNs across sites is crucial. Advanced WMS platforms allow LPNs to be transferred seamlessly between warehouses, maintaining traceability throughout the supply chain.

• Example: A 3PL managing stock for a retail client can easily transfer LPNs between regional distribution centers. This ensures that inventory is always visible and traceable, no matter where it is located in the supply chain.

Real-Time LPN Scanning with Mobile Devices

Many WMS platforms offer mobile apps that allow warehouse workers to scan LPNs in real time, streamlining tasks like picking, packing, and moving inventory. These mobile tools reduce errors and enable faster warehouse operations by instantly updating the system whenever an LPN is scanned.

Key Benefits of LPNs in Warehouse Management

Improved Accuracy and Traceability

LPNs reduce human error by ensuring that each step in the inventory process is tracked electronically. Scanning an LPN eliminates the need for manual data entry, reducing miscounts and misplaced items.

Increased Efficiency and Labor Savings

By grouping items under a single LPN, warehouse workers can move, pick, or store multiple items with a single scan. This dramatically reduces the time required to handle large volumes of stock, improving throughput.

Enhanced Real-Time Visibility

With LPNs, warehouse managers have a real-time view of inventory locations and movement. This is especially valuable for high-turnover environments, where the speed and accuracy of operations are critical.

Support for Complex Warehouse Environments

LPNs simplify inventory management in multi-location, multi-client, and multi-tiered storage environments. Their flexibility allows 3PLs and large-scale warehouses to easily manage diverse product ranges and storage configurations.