Focus on throughput capacity, pick-and-pack accuracy, inventory visibility (real-time WMS), and value-add services (kitting, returns). Also evaluate carrier neutrality, SLA commitments, onboarding timelines, and contingency capacity for seasonality.

Compare storage rates (per pallet/ft²), inbound receiving fees, pick-and-pack labor rates, outbound packaging and dimensional weight impacts, monthly minimums, and chargeback policies. Factor in transportation lanes and average transit days to calculate total cost to serve.

Location determines parcel zone efficiencies, carrier pick density, and driving time for same-day/next-day SLAs. Warehouses closer to major arteries reduce fuel and time costs and expand available carrier windows, improving reliability for omnichannel fulfillment.

Require measurable SLAs for order accuracy, on-time shipments, and inventory reconciliation. Insist on a modern WMS with EDI/API integrations, reporting dashboards, inventory reconciliation tools, and defined escalation processes for exceptions and peak volumes.