Assess throughput and SLA performance (orders/hour, cut-off times), scalability of racking and labor, WMS integration and EDI/APIs, pick accuracy, returns handling and customs support. Validate peak-season staffing, slot utilization and cost-per-order to model total cost-to-serve.

Look for 3PLs with immediate access to air cargo ramps and nearby deep-water terminals, reliable feeder schedules, and short intermodal transfer times. These factors reduce lead times, simplify routing options and support predictable SLA design for cross-border lanes.

Key metrics include order cycle time, picking accuracy, dock-to-stock time, space utilization, labor productivity (lines/hour), and cost-per-order. Include fixed vs variable fee breakdowns, minimum monthly charges and peak surcharges to model true landed cost.

Bonded storage defers duties until goods enter the domestic market, improving cash flow and enabling just-in-time duty payment. Coupled with in-house customs brokerage, it reduces clearance time and inventory dwell, improving velocity and lowering total landed cost.