Prioritize metrics that drive service and cost: transit-time corridors to key customer clusters, terminal and carrier access, dock and bay capacity, racked vs. bulk storage ratios, and local labor availability. Also evaluate WMS/TMS compatibility, SLA guarantees for pick accuracy and order-cycle time, and contingency capacity for seasonal spikes.

Location affects linehaul length, last-mile rates, and dwell time—each feeding into landed cost. Proximity to major carriers and intermodal facilities reduces multi-stop routes and LTL surcharge exposure. Factor in facility operating costs (rent, utilities, taxes) and handling efficiency (picks per hour) to model landed-cost scenarios by channel.

Require native or API-enabled WMS/TMS integrations for real-time inventory, order routing rules, EDI/JSON order flows, and carrier rate shopping. SLAs should specify pick-and-pack accuracy, order-cycle time, on-time shipments, inventory reconciliation cadence, and penalties or remediation for repeated breaches.

Onboarding typically spans 6–12 weeks for standard SKU assortments—covering WMS mapping, inventory migration, and test orders. Complex assortments, kitting, or temperature-controlled SKUs add time. Validate the 3PL’s contingency capacity, seasonal labor plans, and modular racked space to ensure ramp flexibility without capital lease exposure.