On-time delivery: On-Time In-Full (OTIF), on-time shipping (carrier pickup within window), and on-time delivery to end customer, usually tracked against both the 3PL's committed SLA and the customer's expected date.
Order accuracy: Order accuracy rate (percentage of orders picked, packed, and shipped without errors), mis-ship rate, and return-to-sender rate due to fulfillment error.
Fulfillment speed: Order-to-ship time (cycle time from order receipt to dispatch), same-day/next-day fulfillment rate, and dock-to-stock time for inbound receiving.
Inventory accuracy: Cycle count accuracy (system vs. physical inventory), stockout rate, and inventory discrepancy rate — often paired with days of inventory on hand to catch overstock issues too.
Cost: Cost per order/unit shipped, cost per unit stored, freight cost as a percentage of revenue, and accessorial/chargeback frequency (a good proxy for hidden cost creep).
We also layer in a few cross-cutting metrics that tend to surface problems the individual KPIs miss: damage/claims rate, returns processing time, and a customer satisfaction or NPS score tied specifically to fulfillment experience. Happy to share benchmark ranges for any of these if useful for your evaluation.
