Prioritize location relative to your customer base and port gateways, dock and racking capacity, fulfillment SLA performance, WMS integration and real labor rates. Evaluate carrier access and scheduled pickup windows to reduce transit variability and total landed cost.

Review historical throughput, contingency capacity plans, flexible labor models and technology for slotting and batch picking. Confirm the 3PL's ability to add temporary labor, extend shifts, and provide dedicated lanes or cross-dock services during peaks.

Look for efficient pallet racking and density optimization, real-time inventory visibility (WMS), frequent carrier sailings or air options, and cross-dock capabilities to reduce dwell time. Combine that with order consolidation to lower per-shipment costs.

Ask about WMS features, EDI/API integrations, SLAs for accuracy and lead time, insurance and compliance certifications, and existing carrier contracts. Request performance metrics and references that demonstrate consistent on-time delivery and scalability.