Prioritize metrics that align to service goals: on-time shipment rate, order accuracy, dock-to-stock cycle times, inventory turn, and cost per order. Assess capabilities such as multi-temperature storage, cross-docking, returns handling, WMS/API integrations, and customs clearance experience to ensure the 3PL supports both high-volume eCommerce spikes and steady B2B replenishment.

Port proximity reduces feeder and drayage time, improving predictability for inbound replenishment. Limited carrier density can increase rates for urgent lanes, so evaluate frequency of short-sea and air services, consolidation opportunities, and transit reliability. A 3PL with established carrier contracts and consolidation services can materially lower landed cost and transit variability.

Review warehouse layout for storage density and pick productivity, availability of temperature-controlled units, automation potential, and local labor skill levels. Confirm shift patterns, peak-season scalability, and proximity to suppliers or major customers. These factors determine storage efficiency, picking speed, and the true cost-to-serve for different SKU profiles.

Ensure the 3PL has documented customs clearance procedures, local tax and import compliance knowledge, and secure processes for controlled goods. Validate onboarding timelines for WMS integration, EDI/API connections, inventory migration plans, and SLAs for go-live. Clear data exchange and defined escalation paths reduce risk during the transition and ongoing operations.