Storage and Warehousing Industry Terminology

ABC Analysis

A method that categorizes inventory into three tiers (A, B, C) based on value or velocity to focus control and resources where they matter most. A-items are high-value/high-velocity, B-items are mid-tier, and C-items are low-value/low-velocity.

We used ABC analysis to prioritize cycle counts on our A-items weekly; Classify SKUs into A, B, and C before slotting; The CFO wants service guarantees for A-class inventory.

Advanced Shipping Notice (ASN)

An electronic pre-alert from a shipper detailing an incoming shipment (contents, quantities, packaging, and timing). ASNs enable pre-receiving, labor planning, cross-docking, and faster putaway.

Send the ASN by EDI 856 before the truck arrives; Pre-receipt the load using the ASN to cut dock-to-stock time; Mismatch between ASN and actual pallets triggered an exception.

AS/RS (Automated Storage and Retrieval System)

Computer-controlled systems (cranes, shuttles, carousels) that automatically store and retrieve goods from defined locations, improving accuracy, density, and throughput.

The mini-load AS/RS feeds goods-to-person stations; Shuttles increased storage density without adding square footage; We paused the crane for WCS maintenance.

Batch Picking

A picking method where lines from multiple orders are picked together in one pass, then sorted downstream, reducing travel time compared to discrete order picking.

Batch pick 20 orders to reduce aisle travel; The WMS groups small e-commerce orders into a batch; Batch-to-cart works well for our ABC ‘B’ items.

Bill of Lading (BOL)

A legal document issued by a carrier acknowledging receipt of cargo and the terms of transport. It serves as a receipt, a document of title (when negotiable), and a contract of carriage.

We can’t release the shipment without the signed BOL; Check the BOL for NMFC codes; Damage claim requires the original BOL.

Bonded Warehouse

A secured facility authorized by customs where imported goods can be stored without immediate payment of duties and taxes. Goods may be manipulated or re-exported under customs control.

Store imported wine in a bonded warehouse until duties are paid; Bonded space helps cash flow on seasonal imports; Customs audit requires accurate bonded inventory records.

Buffer Stock

Extra inventory held to absorb short-term variability in demand or supply, preventing stockouts and protecting service levels.

We increased buffer stock ahead of the promo; Safety stock and buffer stock serve different purposes in our model; Upstream variability requires a larger buffer.

Capacity Utilization (Warehouse)

The percentage of available storage, throughput, and labor capacity actually used. Measured by cubic utilization, location occupancy, dock door usage, and labor hours consumed.

Cubic utilization hit 92%—time to expand or re-slot; Pallet position utilization is high but labor capacity is constrained; We monitor pick module saturation weekly.

Cross-Docking

An operation where inbound goods move directly to outbound shipping with minimal or no storage, reducing handling, dwell time, and inventory holding.

Cross-dock the fast-movers straight to outbound; ASN accuracy is critical for cross-docking; We set up a flow-through lane for retail allocations.

Cycle Counting

An ongoing inventory audit process that counts a subset of items or locations regularly to maintain high inventory accuracy without shutting down operations.

Daily cycle counts replaced our annual wall-to-wall; Count A-items weekly and C-items quarterly; WMS scheduled a blind cycle count for that location.

Dead Stock

Inventory with little or no demand, often obsolete or beyond its useful selling period, tying up capital and storage space.

Those SKUs are dead stock—time to liquidate; Marketing will bundle dead stock to free space; High dead stock inflates carrying costs.

Demand Forecasting

Estimating future demand using historical data, market intelligence, and models (time series, causal, or machine learning) to drive replenishment and capacity planning.

Use a seasonal model for cold-weather SKUs; Forecast error drives our safety stock; Collaborative forecasting with the retailer improved OTIF.

Dock-to-Stock Time

The elapsed time from receipt at the dock until items are available in inventory for picking. A key metric for receiving efficiency and inventory availability.

We cut dock-to-stock from 8 hours to 2 with ASNs; Temperature checks extended dock-to-stock for frozen SKUs; Putaway labor is the bottleneck in dock-to-stock.

Economic Order Quantity (EOQ)

A formula that determines the order size that minimizes the total of ordering and holding costs, commonly EOQ = sqrt(2DS/H), where D = demand, S = order cost, H = holding cost.

Recalculate EOQ after carrying cost changes; EOQ doesn’t fit promo-driven SKUs; We cap EOQ by pallet layer constraints.

ERP (Enterprise Resource Planning)

Integrated enterprise software that manages core functions (finance, procurement, manufacturing, inventory, and order management) and often interfaces tightly with WMS and TMS.

WMS posts inventory updates back to the ERP; ERP master data errors caused ASN mismatches; Finance closes rely on ERP inventory valuation.

FEFO (First Expired, First Out)

A stock rotation policy that prioritizes items with the earliest expiration date, essential for perishable and regulated goods.

FEFO rules for all chilled products; Override FEFO for the recall lot; Date codes drive FEFO allocation to stores.

FIFO (First In, First Out)

A stock rotation policy where the oldest inventory (by receipt date) is shipped first, reducing aging and write-offs.

FIFO reduces obsolescence on electronics; Our pallet flow lanes enforce FIFO; Break FIFO only for a quality hold release.

Fill Rate

The percentage of customer demand that is fulfilled immediately from available stock. Measured by order, line, case, or unit fill rates.

We target a 98% line fill rate; Low case fill rate triggered an RCA; Safety stock raised order fill performance.

Floor Loading (Floor-Loaded)

Shipping cartons stacked directly on a trailer or container floor without pallets, increasing space efficiency but requiring more handling to unload.

Import containers are floor-loaded to maximize cube; Floor loading adds time at receiving; We negotiated a floor-load surcharge with the 3PL.

Goods-to-Person (G2P)

Automation that brings items to stationary operators for picking or packing, improving throughput, ergonomics, and accuracy.

G2P cut picker travel by 80%; Shuttle G2P supports 1,000 lines/hour per station; Integrate G2P with WES for dynamic waves.

HAZMAT (Hazardous Materials) Handling

Specialized storage and handling of hazardous goods compliant with regulations (e.g., OSHA, DOT, ADR), including segregation, labeling, documentation, and training.

Segregate oxidizers per HAZMAT regs; HAZMAT training is required for all forklift drivers; Placards and SDS must be available at receiving.

Inventory Accuracy

The degree to which system-recorded inventory matches physical counts by quantity, location, status, and lot/serial attributes.

Cycle counting improved inventory accuracy to 99%; Slotting errors hurt location accuracy; We reconcile WMS vs. ERP inventory weekly.

Inventory Turnover

How many times inventory is sold or used in a period, typically COGS divided by average inventory, indicating capital efficiency and freshness.

Turnover improved from 5x to 8x after SKU rationalization; Low turns indicate excess safety stock; We benchmark turns by category.

JIT (Just-in-Time)

A strategy to receive goods only as needed to minimize inventory carrying costs, relying on reliable suppliers and short lead times.

JIT deliveries to the line reduced on-hand inventory; Port delays broke our JIT model; We set min/max to buffer JIT variability.

Kanban

A visual pull system (cards, bins, or digital signals) that triggers replenishment based on actual consumption, limiting WIP and overproduction.

Two-bin Kanban for fasteners in maintenance; Digital Kanban signals trigger replenishment tasks; Kanban levels adjusted for seasonality.

Kitting

Combining separate components into a ready-to-use kit before shipment or production, often as a value-added service.

Pre-kitting reduces assembly time at stores; Create a virtual kit in the WMS for wave planning; Quality checks at the kitting cell caught shortages.

Lean Warehousing

Applying lean principles to warehouse operations to eliminate waste (motion, waiting, overprocessing), improve flow, and increase value to the customer.

We applied 5S to the packing area; Kaizen event cut pick path waste by 20%; Value stream mapping exposed putaway delays.

Lot/Batch Control

Tracking inventory by lot or batch number for traceability, quality control, and compliance. Enables targeted recalls and expiration management.

Trace that lot across all outbound orders; FEFO requires accurate lot dating; Recall containment depends on lot-level visibility.

Material Handling Equipment (MHE)

Equipment that moves, stores, controls, and protects materials, including forklifts, pallet jacks, conveyors, carousels, AS/RS, AGVs, and AMRs.

Upgrade to lithium-ion forklifts to cut downtime; AMRs are part of our MHE roadmap; Conveyor uptime is tracked in the WCS.

OTIF (On Time, In Full)

A customer service metric measuring whether deliveries arrive by the promised time and with complete quantities. Often contractual with financial penalties.

Retail penalties for OTIF misses are steep; Carrier delays hurt our OTIF last quarter; We monitor OTIF by DC and lane.

Palletization

Unitizing goods on pallets for handling and storage. Involves choosing pallet types, footprints, stacking patterns, and securing methods (wrap, straps, glue).

Standardize on GMA 48x40 pallets; Use slip-sheets to reduce pallet cost; Optimize pallet patterns for stability and cube.

Pick-to-Light / Put-to-Light

Light-directed systems where displays indicate pick/put locations and quantities, enabling fast, high-accuracy picking and sorting.

PTL improved e-com picking accuracy to 99.8%; Use put-to-light for order consolidation; LEDs guide multi-order batch picking.

Putaway

The process of moving received goods from the dock to assigned storage locations, often directed by WMS rules for space and accessibility optimization.

Directed putaway uses rules by velocity and size; Cross-docked cartons skip putaway; We added QC holds during putaway for returns.

Racking Systems

Structured storage systems such as selective, drive-in/drive-through, push-back, pallet flow, and cantilever racks, balancing density with accessibility.

Switch selective racks to push-back for higher density; Pallet flow supports FIFO; Cantilever racks store long profiles.

RFID (Radio Frequency Identification)

Wireless identification using tags and readers to capture item or pallet data without line-of-sight, improving visibility and accuracy.

RFID portals automate receiving counts; Item-level RFID enables self-check at pack-out; Metal interference required tuned tags.

Safety Stock

Extra inventory held to protect against demand and lead-time variability. Typically calculated using service levels, demand variability, and lead-time uncertainty.

Raise safety stock during supplier changeover; Service-level targets drive safety stock calculations; We separate cycle stock and safety stock in the WMS.

SKU (Stock Keeping Unit)

A unique identifier for a distinct product, defined by attributes such as size, color, and configuration, used for tracking and inventory control.

Each size/color is a separate SKU; SKU proliferation increased slot count; We retired 15% of SKUs after a Pareto review.

Slotting Optimization

Strategically assigning SKUs to specific locations to reduce travel, balance workload, and improve ergonomics based on velocity, size, and affinity.

Re-slot A-items to golden zones; Family slotting groups hazmat-compatible SKUs; Velocity slotting cut pick travel by 30%.

Storage Density

The amount of inventory stored per unit of space (cubic or square), reflecting how efficiently space is used, often traded off against accessibility.

Drive-in racks increased storage density but cut selectivity; Floor stacking maximizes density for full pallets; We measure cubic feet per pallet stored.

Supply Chain Visibility

The ability to see and track orders, inventory, and shipments end-to-end in near real time, enabling proactive exception management and better decisions.

Track in-transit inventory with IoT sensors; Control tower dashboards improved visibility; Real-time ETA feeds informed dock scheduling.

Third-Party Logistics (3PL)

A provider that performs logistics services such as warehousing, fulfillment, and transportation on behalf of a client, often under service-level agreements.

Outsource e-commerce fulfillment to a 3PL; Our 3PL’s WMS integrates via APIs; Conduct a QBR with the 3PL on KPIs and SLAs.

Throughput

The rate at which a facility processes items, lines, cartons, or pallets over time. A key capacity and productivity measure.

Peak throughput is 12k order lines/hour; The sorter is our throughput constraint; Add labor to sustain throughput during promos.

TMS (Transportation Management System)

Software that plans, executes, and optimizes the movement of goods, including carrier selection, rating, tendering, tracking, and freight settlement.

TMS optimizes multi-stop routes from the DC; Tender loads and track ETAs in the TMS; Freight audit and pay are handled by the TMS.

Value-Added Services (VAS)

Custom operations performed in the warehouse beyond basic storage and picking, such as labeling, bundling, kitting, customization, and postponement.

VAS includes labeling, kitting, and light assembly; Retailer-specific VAS adds cost per unit; We priced VAS separately in the 3PL contract.

Vendor-Managed Inventory (VMI)

A replenishment model where the supplier monitors the customer’s inventory and makes restocking decisions, often improving service and reducing bullwhip effects.

Suppliers replenish via VMI at our DC; Share POS data to improve VMI performance; VMI cut stockouts on B-class SKUs.

Warehouse Control System (WCS)

Software that controls and coordinates real-time equipment (conveyors, sorters, AS/RS), translating high-level work from WMS/WES into machine instructions.

WCS orchestrates conveyors and sorters in real time; Hand off waves from WMS to WCS; PLC changes require WCS updates.

Warehouse Execution System (WES)

Software that optimizes and orchestrates work across people and automation on the warehouse floor, often providing dynamic order release, labor balancing, and exception handling.

WES enabled waveless picking during peaks; Dynamic load balancing across G2P stations via WES; WES sits between WMS and WCS.

Warehouse Management System (WMS)

Core warehouse software that manages inbound, storage, picking, packing, shipping, inventory control, and task management with real-time location tracking.

Configure directed putaway rules in the WMS; WMS cycle count module improved accuracy; Integrate WMS with TMS for ship confirmations.

Yard Management System (YMS)

Software that manages yard operations outside the warehouse, including gate check-in, trailer spotting, dock-door assignment, and yard visibility.

YMS schedules dock appointments and tracks trailers; Use yard jockeys based on YMS moves; Yard checks are automated via YMS RFID.

Zoning (Warehouse Zones)

Dividing the warehouse into areas for storage or work by product type, temperature, hazard class, velocity, or process to improve control and efficiency.

Zone picking limits picker travel; Create temperature-controlled zones for FEFO; HAZMAT requires segregated zones.