Prioritize throughput (picks per hour), WMS/API integration and real-time inventory visibility, carrier lane coverage and parcel/LTL contracts, SLA terms for order cycle time and returns, peak‑season scalability, and data/reporting. Validate dock capacity, slotting strategy, labor flexibility and KPIs to ensure the provider meets your fulfillment model.

Closer proximity typically reduces drayage and inland transit time, increases modal choices (truck, intermodal, air) and shortens replenishment cycles. Quantify tradeoffs by assessing port congestion risk, container detention and intermodal frequency to determine net landed cost versus lead‑time improvements.

Require a modern WMS with real‑time inventory, API/EDI connectivity, scalable racking and high clear heights, automated sortation or pick‑to‑light where justified, yard management and quality control processes. These reduce touches, errors and cost‑per‑pick while improving throughput.

Review each 3PL’s carrier network including parcel contracts, LTL partners, regional carriers and dedicated van lanes; check pickup frequency, transit‑time maps and freight audit processes. Request carrier performance metrics (OTD, claims rate) and test transit to priority ZIPs to validate coverage and cost‑to‑serve.