Supplier Performance Calculator
Measure a supplier's reliability by calculating their on-time delivery rate as a percentage of all shipments received. Use this to benchmark vendors, support contract reviews, and identify fulfillment risks in your supply chain.
About this calculator
On-time delivery (OTD) rate is one of the most widely tracked supplier KPIs in supply chain management. The formula is: OTD Rate (%) = (onTimeDeliveries / totalDeliveries) × 100. A delivery is counted as 'on time' when it arrives within the agreed-upon delivery window specified in the purchase order. Tracking this metric regularly helps procurement teams identify chronic late suppliers before they cause stockouts or production delays. World-class supplier performance typically targets an OTD rate of 95% or higher. When OTD falls below threshold, it triggers supplier development actions, penalty clauses, or sourcing diversification. This single metric is often the foundation of a broader supplier scorecard alongside quality and cost measures.
How to use
Imagine you are evaluating a supplier over a quarter. They made 120 total deliveries, of which 108 arrived within the agreed delivery window. Step 1: Identify inputs — onTimeDeliveries = 108, totalDeliveries = 120. Step 2: Apply the formula: (108 / 120) × 100. Step 3: Divide first: 108 / 120 = 0.90. Step 4: Multiply by 100: 0.90 × 100 = 90%. The supplier's OTD rate is 90%, which is below the typical 95% benchmark, flagging them for a performance improvement conversation.
Frequently asked questions
What is a good on-time delivery rate for a supplier?
A commonly accepted benchmark for world-class supplier OTD performance is 95% or above. Many automotive and aerospace supply chains set the bar even higher, targeting 98–99% due to just-in-time production requirements. Rates below 90% are generally considered problematic and typically trigger formal corrective action requests. The right target depends on your industry, lead times, and the safety stock buffer you carry — a supplier serving a low-inventory lean line needs a much higher OTD standard than one supplying slow-moving MRO items.
How do I calculate supplier on-time delivery rate accurately?
Accuracy starts with a clear definition of 'on time' — this should be tied to the original purchase order delivery date, not a revised date agreed after the fact. Count each delivery line or shipment as a single unit of measurement and apply the formula: OTD% = (onTimeDeliveries / totalDeliveries) × 100. It is best practice to measure over a rolling 90-day or quarterly window to smooth out seasonal fluctuations. Exclude force-majeure events (port strikes, natural disasters) only if your contract explicitly allows it, and document all exclusions consistently.
Why is supplier on-time delivery performance important for inventory management?
Late deliveries directly erode your ability to maintain target inventory levels, leading to stockouts, emergency freight costs, and potential line stoppages. A supplier with a poor OTD rate forces you to carry higher safety stock buffers to compensate, which ties up working capital unnecessarily. Tracking OTD systematically enables data-driven sourcing decisions — replacing or dual-sourcing chronically late vendors before the problem escalates. It also creates accountability in supplier relationships, as vendors who know their delivery data is tracked and reported tend to prioritize your orders more carefully.