Prioritize a 3PL with a modern WMS and reliable API/EDI integrations, scalable slotting and labor plans, multi-temperature storage if required, efficient returns processing, and documented SLAs for order accuracy and on-time dispatch. Also confirm network reach for last-mile carriers and peak-season labor scalability.

Proximity to primary highways and regional freight corridors reduces linehaul and last-mile miles, lowering transit time and LTL costs. Access to intermodal terminals or nearby ports enables bulk inbound consolidation. Evaluate carrier density, scheduled pickup windows, and regional hub clustering to optimize routing and carrier rates.

Analyze space and racking rates, labor and benefits, utilities, inbound/outbound handling charges, pick-and-pack fees, minimums, inventory carrying costs, and returns handling. Model cost-to-serve by SKU velocity and order profile to capture slotting, batching, and seasonal labor impacts on unit economics.

Require real-time inventory visibility through a WMS with APIs, event-based notifications, and customizable dashboards. Define KPIs (OTD, order accuracy, cycle count variance), cadence for SLA reviews, and access to audit trails and EDI/order flow for root-cause analysis. Confirm security and backup procedures for data and operations.