Benchmark pick/pack accuracy, order cycle time, on-time delivery rate, inventory shrinkage, and throughput per labor hour. Negotiate SLAs with clear penalties, liability for lost/damaged goods, inventory reconciliation cadence, and defined onboarding milestones to align operational and commercial expectations.

Model landed cost by combining facility costs, inbound freight, handling fees, carrier rates for last‑mile, and average dwell time. Run time‑in‑transit simulations to key customer clusters and include peak-season surcharges and reverse-logistics expenses for a comprehensive cost-to-serve view.

Require a WMS with real-time inventory, API connectivity for marketplace and carrier integrations, batch/lot tracking, multi-warehouse orchestration, and support for returns processing workflows. Verify reporting cadence, EDI/API test plans, and contingency procedures for system outages.

Request a site visit and historical throughput data for comparable clients, inspect racking and staging capacity, review labor pool metrics and peak staffing plans, and include volume-based performance milestones and flexible capacity clauses in the contract to accommodate growth or seasonality.