Prioritize carrier reach and mode mix (FTL/LTL, rail), proximity to major highways, and WMS capability for real-time inventory. Evaluate SLA terms, chargeback policies, and value-add services such as kitting, returns processing, and quality inspection to align cost-per-order with service expectations.

Facility attributes — racking density, clear height, dock count, cross-dock capability, and temperature control — directly affect throughput and cost. Also assess automation readiness, staging areas for pick-and-pack, and peak staffing plans to ensure consistent order cut-off times and reduced transit exceptions.

Require WMS with API/EDI for order/inventory sync, daily inventory accuracy KPIs, on-time shipment rate, order cycle time, and shrinkage metrics. Prefer 3PLs that provide dashboarding, exception alerts, and integration with marketplaces and carrier systems to streamline operations.