Prioritize order accuracy, on-time-in-full (OTIF), dock-to-stock throughput, average pick/pack cycles per hour, and returns processing time. Also review penalty/chargeback clauses, SLA measurement cadence, reporting granularity, and how the 3PL manages exceptions and seasonal spikes.

Evaluate proximity to primary road arteries and port feeders, intermodal handling capability, staging yards for trailers, dock configuration, available lift equipment, and local carrier density. These determine truck turn times, multimodal options, and shipment reliability for B2B lanes.

Key cost drivers are facility rent, labor (picks/hour), transportation, inventory carrying, and value-added operations. Savings often come from slotting optimization, consolidation to reduce parcel zones, improved forecasting to lower safety stock, and selective automation in high-throughput zones.

Seek flexible rate tiers (base + activity), clear SLA definitions with KPI-linked rebates/penalties, seasonal capacity clauses, short notice scale-up options, transparent fee schedules for value-added services, and exit terms that protect inventory and customer continuity.