Prioritize measurable KPIs and facility specs: on‑time order cycle, picks per hour, dock door count, racked capacity and ceiling height, security and cross‑dock capability, and technology (WMS/API support). These metrics reveal whether a 3PL can meet peak volume, same‑day shipping needs, and SLA commitments.

Carrier connectivity directly affects transit time variability and routing cost. Warehouses near major highways, LTL terminals, or intermodal yards lower mileage charges and expedite next‑day deliveries. Assess proximity to dominant parcel and LTL hubs, typical transit lanes, and freight tender success rates to estimate landed‑cost improvements.

Compare unit and fixed fees, storage (per pallet/sqft), pick/pack rates, inbound handling, dock/appointment charges, value‑added services, and short‑term labor premiums. Also evaluate minimums, volume tiers, billing cadence, liability terms, and pass‑throughs for carrier fuel or accessorials to model true cost‑to‑serve.

Require real‑time inventory sync via API or EDI, order acknowledgements, ASN capability, shipment tracking callbacks, and daily inventory reports. Define SLAs on accuracy, order cycle time, and chargeback thresholds, plus escalation paths and root‑cause reporting to enforce performance and minimize fulfillment exceptions.