Prioritize inventory accuracy (cycle counts, error rates), order lead times, SLA guarantees for pick/pack/ship, returns handling workflow, and integration capability (API/WMS). Also validate carrier partnerships and last-mile reach to your customer segments to maintain consistent delivery windows.

Map primary lanes and request transit-time reports and on-time percentages from prospective 3PLs. Assess multimodal options (road vs. rail), frequency of scheduled departures, capacity constraints, and historical border clearance times to model expected lead-time variability.

Compare storage by pallet and cubic pricing, unit pick fees, handling for inbound pallets, kitting and value-added service rates, minimum monthly charges, and surcharges (seasonal, fuel, customs). Model total landed cost per SKU across forecasted volumes.

Inspect racking and clear height, dock capacity, security systems, temperature control, and fire suppression. Verify WMS capabilities, EDI/API integration, batch/lot traceability, staff training, and any relevant customs/bonded facility certifications or permits.