Require clear KPIs such as order lead time, pick-and-pack accuracy, inventory accuracy, on-time shipping, and return processing times. Contractual penalties or service credits for misses and regular operational reviews ensure continuous improvement and alignment between your fulfillment expectations and the 3PL's performance.

Compare landed shipping costs versus inventory carrying costs, expected transit-time improvements, and service-level targets. Factor in SKU velocity, seasonal demand, and complexity of managing multiple integrations; pilot smaller nodes to validate cost-to-service improvements before full rollout to a distributed network.

Prioritize warehouses with direct access to major road arteries, consolidation and cross-dock facilities, in-house or partnered customs brokerage, and strong relationships with regional carriers and freight forwarders to streamline documentation, reduce dwell time, and lower inland transport costs.

Key steps include data migration and SKU mapping, WMS/API integration and testing, SOP alignment, pilot order volumes, staff training, and staged cutover. Establishing a clear timeline, acceptance tests, and escalation paths reduces risk and shortens the stabilization period after go-live.