Assess throughput metrics (lines/orders per hour), peak handling history, slotting and staging capabilities, seasonal labor plans, and ramp-up speed. Verify WMS capacity, cross-dock options, and SLAs for order cycle time to ensure the 3PL can sustain peak velocity without service degradation.

Prioritize port/feeder access, frequency of regional carrier services, dock and yard turnaround times, and local last-mile partners. Confirm carrier contracts, consolidation lanes, transit-time maps, and pickup schedules to optimize rate and reliability for B2B lanes.

Require secure receiving and inspection, multi-temperature storage, realtime WMS integration, returns and reverse-logistics processing, kitting/assembly, and compliance documentation. Ensure insurance, audit trails, and local regulatory adherence for cross-border and inbound shipments.

Model fixed versus variable costs: storage, labor (picks/hrs), packing materials, inbound/outbound freight, and value-added fees. Run scenario-based volumes and SKU mixes to calculate per-order and per-SKU cost-to-serve, include service penalties, and stress-test peak-season assumptions before comparison.