Prioritize demonstrated port/airport handling, multimodal transfer procedures, IT and WMS integration, SLA metrics (inventory accuracy, order cycle time), contingency plans for weather-disrupted shipping, and the 3PL’s experience with seasonal demand variability and returns workflows.

Key cost drivers include mode mix (sea vs. air), frequency of sailings and flights, consolidation efficiency, last-mile ferry or barge fees, storage density, and handling for special products. Transit-time variability is affected by sailing schedules, weather windows, and cross-docking capabilities.

Many providers can support omnichannel needs, but verify reverse-logistics processes, returns disposition options, kitting and rework capacity, pick-and-pack throughput, EDI/API connectivity, and SLA-backed cut-off times to ensure consistent omnichannel execution.

Include SLAs for inventory accuracy, order fill rate, on-time shipments, cut-off and processing times, penalties for missed SLAs, disaster-recovery plans for port/airport disruptions, and clearly defined responsibilities for customs, documentation, and force-majeure events.