Prioritize proximity to interstates, ports, and rail yards for inbound speed; carrier density for competitive rates; facility configuration for your SKU profiles (racked vs. bulk); cross-dock and stage capacity for flow-through orders; and proven peak-season scalability to avoid service degradation.

Confirm WMS capabilities (inventory visibility, lot/serial control), API/EDI connectivity, real-time order and shipment status, reporting granularity, and test integration support. Ask for sample data feeds, SLA response times, and change-management processes for upgrades or custom workflows.

Compare storage (per pallet/cubic foot), inbound receiving, pick-and-pack per unit, kitting, returns processing, handling minimums, accessorials (overages, OT), labeling, transportation margins, and chargeback exposure. Model scenarios for average order size and peak-season volume.

Labor availability impacts throughput and overtime costs. Evaluate a provider's reliance on temp labor, relationships with staffing agencies, automation investments, and contingency plans (additional shifts, cross-training). Clear surge staffing plans reduce SLA risk during peaks.