Prioritize inventory visibility (WMS/real‑time reporting), SLA adherence for picking and shipping, multi‑temperature storage if needed, returns handling and reverse logistics, and the partner’s ability to scale labor and space seasonally. Also verify carrier integrations and last‑mile coverage for your target customer regions.

Cost‑to‑serve breaks down costs by SKU, channel, and route to reveal true fulfillment drivers: storage days, pick complexity, packaging, and outbound freight zones. Use it to compare provider pricing models, identify consolidation or zone skipping opportunities, and balance inventory allocation across the network.

Key metrics include proximity to highways and rail terminals, dock capacity and throughput rates, racking and clear height, availability of temperature control, on‑site handling equipment, and carrier density for first/last‑mile options. Also assess IT integration readiness and uptime guarantees.

Require clear SLAs for order accuracy, on‑time shipment, and inventory reconciliation; real‑time EDI/API integrations with your ERP and marketplaces; procedures for exceptions and returns; audited security and contingency plans; and defined escalation paths and penalties for SLA breaches.