Prioritize WMS functionality and API/EDI integration, defined SLAs for order accuracy and transit times, dock and racking capacity for your SKU mix, labor availability during peaks, and returns handling processes. Verify reporting, KPI cadence, and onboarding timelines to assess readiness for scale.

Carrier density and short transit lanes lower freight rates and reduce safety stock needs. Faster transit reduces inventory carrying costs and enables tighter reorder points. Evaluate carrier mix, multimodal options, and local last-mile partners to balance cost with service-level objectives.

Assess flexible capacity, third-shift or seasonal labor pools, WMS rules for wave picking and slotting, kitting and value-added services, returns processing throughput, and availability of climate-controlled storage. Confirm contingency plans for surges and system failover.

Key factors include transparent pricing (picking, storage, accessorials), minimum-volume commitments, SLA definitions with remedies, indexation clauses for labor or energy, onboarding and exit terms, and visibility into cost-to-serve calculations to avoid future disputes.