Warehouse Management System - slot-occupancy overview
All pallet positions emptyFew positions emptyNo positions emptyPallets in receiving areaAisle spacesVehicle at dock
A WMS maps the physical warehouse - inbound/outbound docks, aisles and every pallet position, colour-coded by occupancy - so operators see at a glance where space is free and where product is waiting to be put away.
Attribute
WMS
TMS
Full name
Warehouse Management System
Transportation Management System
Focus
Activities inside the warehouse/facility
Material movement between facilities
Scope
Receiving → Put away → Storage → Picking → Dispatch
Freight, routing, dock scheduling, yard management
Facility types
Warehouse, DC, fulfillment center, sort center, cross-dock
Long-haul, last-mile, inter-facility transport
Linked to
ERP (materials module), TMS
ERP (vendor module), WMS
Developed
In-house or procured (same or different vendor as ERP)
Warehouse activities are very specific to the product type, facility layout, and process - not common across all businesses. ERP handles common business functions (finance, HR, projects) - not granular warehouse ops. WMS and ERP are often from the same vendor but are separate modules - integration is required.
Put Away: Items moved from inbound to designated storage location. WMS provides sequencing to minimize travel. Location assigned based on SKU movement speed, size, etc.
Storage: Items held for planned duration. WMS shows real-time pallet position availability. Tracks utilization by zone, rack, position.
Picking: Orders received → WMS generates pick list (sequence + quantity). Picker or automated equipment follows list. Picking order minimizes travel distance.
Staging & Dispatch: Picked items moved to outbound area (staging). Loaded onto vehicle. Outbound GRN-equivalent generated. Dock allocated by TMS.
Shows top-view of warehouse - pallet positions: full, empty, partially empty. Color-coded by status. Instant snapshot of capacity utilization.
Space Allocation / Slotting
Decision support: where to assign SKUs based on movement speed (fast-movers near outbound), size, product type. Suggests optimal pallet position for each incoming product.
Goods Receipt Management
Records inbound completion - all pallets unloaded? GRN generated? Integrated with T&T scanning. Links to ERP materials module.
Put Away Sequencing
Tells operator: visit position A first, then B - minimizes travel distance. Also handles multi-pallet put away sequencing.
Pick List Generation
Based on orders received - generates ordered pick list with quantities and locations. Assigns pickers and equipment. Minimizes travel; handles partial and bulk picks.
Which vehicle goes to which dock? When will a dock be free? Assign next vehicle. Connects TMS with WMS - dock availability depends on warehouse pick/load progress.
Yard Management
Manages open space - parking of vehicles awaiting dock allocation. Positioning of heavy equipment (cranes, forklifts). Tracks what is in the yard and when it needs to move.
Freight Management
Mode selection: road vs sea vs air - decision support based on cost, speed, urgency. FTL vs LTL decisions to maximize vehicle utilization. Compares freight costs across options.
Documentation
Auto-generates shipping documents, delivery orders, customs paperwork. Handles regulatory/compliance requirements for inter-state or international shipments.
Vehicle Routing
For last-mile / multi-stop deliveries: decides optimal order of retail stores to visit. Minimizes total distance/time. Determines backhaul: return to warehouse or proceed to another pickup?
All three systems are interrelated - data flows between them continuously:
Integration
Data Flow & Purpose
ERP ↔ WMS
Production schedule informs warehouse of expected inbound. Dispatch records update ERP materials module. Spend data flows to ERP finance.
ERP ↔ TMS
Vendor delivery schedules from ERP procurement module inform TMS dock scheduling. Freight costs flow back to ERP for spend analysis.
WMS ↔ TMS
WMS tells TMS when dock is clear and items are ready for loading. TMS tells WMS vehicle arrival time so dock can be pre-cleared.
WMS ↔ T&T
Barcode/RFID scans at inbound dock update WMS inventory in real time. Pick scan confirms what has been picked and loaded.
TMS ↔ T&T
Vehicle tracking (GPS, telematics) updates TMS with live vehicle location and delivery confirmation at customer point.
End-to-end flow example: Production completes at factory (ERP) → truck dispatched (TMS) → arrives at dock (WMS dock scheduling) → items scanned in (T&T → WMS) → pick list generated for retail orders (WMS) → vehicle routed to stores (TMS).