TI/HI represents foundational metrics in logistics and supply chain management, offering a standardized way to define how products are stacked and shipped. These acronyms stand for “Tie” (or “Tier”) and “High,” and they serve as common language for configuring unit loads. These measurements directly influence decisions regarding storage, transportation, and inventory control throughout the supply chain.
What Tie (TI) and High (HI) Mean
TI, or Tie, refers to the number of individual units, typically cases or cartons, arranged on a single layer of a pallet. This metric is determined by the size and orientation of the product packaging relative to the dimensions of the base pallet. For instance, on a standard 48-inch by 40-inch pallet, the TI calculation ensures the maximum number of cases fit without overhang, preventing product damage. The TI layer establishes the foundational footprint for the entire pallet load, dictating how all subsequent layers must be stacked.
HI, or High, represents the total number of layers, or tiers, stacked vertically from the pallet base to the top of the load. This number is constrained by several physical and structural factors. Limitations on HI include the available ceiling height in a warehouse, the maximum weight capacity of the pallet itself, and the structural integrity of the product packaging. Maximizing HI utilizes space efficiently but introduces greater risk to the goods at the bottom of the stack.
Applying TI and HI to Calculate Pallet Loads
The practical application of TI and HI is centered on a simple calculation that determines the entire contents of a standardized unit load. By multiplying the number of units per layer (TI) by the number of layers (HI), companies establish the total number of items on a finished pallet. For example, if a product has a TI of 10 and an HI of 5, the total number of units per pallet is 50. This straightforward formula provides a consistent and measurable standard for all parties involved in the distribution process.
This calculation is used by manufacturers to prepare products for shipment and by distributors to manage inventory expectations. Knowing the unit count allows businesses to determine necessary packaging materials and accurately quote freight costs based on pallet count. The TI/HI metric also helps establish minimum order quantities for wholesale buyers, ensuring orders are placed in full-pallet increments. This streamlines handling, maximizes transportation efficiency, and optimizes the loading of trucks and containers.
How TI/HI Optimizes Warehouse Operations
Strategic implementation of the TI/HI ratio improves warehouse and distribution center operations. In inventory management, these metrics allow for accurate cycle counting, as staff count full pallets and multiply by the known unit count, rather than counting individual cases. This knowledge is used to determine inventory slotting, ensuring rack locations hold the exact number of units corresponding to a standardized pallet load. Standardizing the unit load minimizes handling time and reduces errors associated with manual counting and breaking down partial loads.
The clear definition of a pallet load also informs purchasing and ordering processes across the organization. Buyers can place orders in predetermined full-pallet quantities, which reduces the need for less-than-truckload shipments and maximizes freight consolidation. This approach ensures that incoming shipments are immediately ready for put-away or direct cross-docking, eliminating the need to reconfigure or recount products upon arrival. Maximizing the HI component, within safe limits, translates to better space utilization by efficiently using the cubic capacity of storage racks and transportation trailers.
Safety and Stability in Pallet Stacking
While maximizing the TI and HI numbers improves efficiency, physical engineering and safety constraints limit the final pallet configuration. The weight of the entire stacked load must never exceed the maximum dynamic weight capacity of the pallet itself, the forklift equipment, or the designated warehouse racking system. Exceeding these weight limits introduces safety hazards and risks structural failure within the storage environment. Therefore, the HI number often represents a balance between maximizing space and respecting equipment specifications.
Maintaining stability is achieved through interlocking stacking patterns, often referred to as brick stacking, where cases on each layer are rotated relative to the layer below. This method prevents vertical columns from forming and ensures the load acts as a single, cohesive unit, which is important when maximizing the vertical height (HI). Excessive HI can compromise product integrity, as the crushing weight of the upper layers may damage fragile goods on the bottom tier. Safety standards may impose absolute maximum height restrictions on stacked loads, irrespective of the product size, to ensure safe visibility and handling by material moving equipment.