Prioritize carrier integration (seaplane and cargo boat schedules), cold‑chain capability if supplying perishables, local customs handling, penalties for missed windows, and the 3PL’s experience with inter‑island routing. Assess SLA adherence, inventory visibility tools (WMS), and contingency plans for weather disruptions.

Geography increases reliance on scheduled maritime and air links, which can extend transit windows and raise cost-to-serve for low-density routes. Consolidation, optimal inventory placement, and timed departures reduce per‑unit costs. Evaluate the 3PL’s network optimization and carrier contracts to manage frequency and rates.

Confirm the 3PL’s ability to process customs declarations, handle bonded storage, manage duties and taxes, and provide digital manifesting to expedite clearance. Verify relationships with local customs brokers, contingency procedures for inspections, and SLA metrics for clearance times.

Cold‑chain reliability is critical: check temperature‑controlled storage, redundant power, temperature monitoring, and validated handling procedures. Also evaluate kitting, B2B order batching, reverse logistics and secure storage for high‑value items to reduce spoilage and shrink.

Track on‑time delivery rates, order cycle time, fill rate, inventory accuracy, cost‑per‑order, and customer returns processing time. For island operations include carrier departure adherence, customs clearance latency, and cold‑chain breach incidents to measure service reliability and cost efficiency.