Prioritize carrier and feeder schedule reliability, warehouse footprint relative to demand centers, cold-chain capability if needed, cross-dock and kitting services, and measurable SLAs (OTIF, order cycle time). Also evaluate customs handling, seasonal capacity, and systems integration (WMS/API) for order visibility.

Expect shorter last-mile delivery windows to island customers but potentially higher per-unit sea freight and handling versus mainland. Cost components include feeder/port fees, inter-island conveyance, terminal handling, and any premium for time-definite service; optimized inventory placement can offset those fees by reducing expedited moves.

Require scalable receiving and returns processing, reverse logistics workflows, quality inspection, kitting/assembly, and temporary storage capacity. Ensure the 3PL can flex labor and carrier options seasonally and report real-time KPI dashboards to manage peaks and maintain SLA compliance.

Look for a modern WMS with API connectivity to order management systems, real-time inventory visibility, exception alerts, and carrier booking integrations. Support for batch tracking, shelf-life controls for cold-chain, and automated reporting are key to reducing manual reconciliation and improving OTIF performance.