Prioritize facility proximity to major transport corridors, minimum viable throughput capacity, value-added services (kitting, returns processing), SLA guarantees for pick-and-pack and order fill, and carrier integrations for regional and last-mile delivery. Verify scalability and contingency plans for peak seasons.

Assess each 3PL's network of regional carriers, frequency of departures to primary ports, and existing contracts for consolidated LTL or FCL services. Request transit-time matrices, sample route maps, and historical on-time departure data to quantify routing efficiency.

Main cost drivers are storage density, labor rates, handling complexity, and inbound/outbound frequency. Optimize by consolidating SKUs, improving forecast accuracy to reduce dwell time, negotiating tiered pricing for volume, and selecting facilities with compatible racking and automation levels.

Require real-time WMS connectivity (API or EDI), inventory sync across channels, order routing rules, and standardized reporting (inventory aging, order cycle times, exceptions). Confirm testing windows for integration and SLAs for data latency to support omnichannel fulfillment workflows.