Lead Time Estimator
Estimate total procurement or production lead time across supply chain stages.
Calculator
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Total lead time: 42 days
Formula
Total lead time = Σ (time for each stage): Supplier processing + Transit time + Receiving & inspection + Production/assembly + Quality check + Dispatch + Delivery to customer.
Example calculation
Supplier processing 7 days + Sea freight 21 days + Port clearance 5 days + Receiving/inspection 2 days + Production 5 days + QC 1 day + Dispatch 1 day = Total 42 days.
Engineering notes
Use P50 (median) lead times for planning and P90 (90th percentile) for customer commitment dates to account for variability. Track actual lead times vs estimates and update your lead time database regularly to improve forecast accuracy.
When to use this calculator
- Customer delivery commitment — calculate realistic delivery dates for order confirmation
- Reorder point calculation — set inventory reorder points based on total replenishment lead time
- Project scheduling — build supply chain timelines for capital projects with long-lead equipment
- Safety stock sizing — use lead time variability data to calculate required safety stock
- Supplier evaluation — compare total lead times across alternative suppliers including quality hold time
Frequently asked questions
- What is the difference between lead time and cycle time?
- Cycle time is the time to complete one unit of work within a single process step. Lead time is the total elapsed time from request to delivery — it includes cycle times plus all waiting times between steps. Lead time is almost always much longer than the sum of cycle times because of queue time, batch processing delays, transit, inspection, and administrative steps. Lean manufacturing targets reducing lead time by eliminating non-value-added waiting.
- How do I reduce procurement lead time?
- Strategies: (1) Supplier development — work with suppliers to reduce their processing time through orders, forecasts, and capacity planning. (2) Safety stock — carry buffer stock to decouple customer orders from supply lead time. (3) Multiple sourcing — qualify alternative suppliers to reduce dependency on a single source with long lead time. (4) Local sourcing — trade off higher unit price for shorter transit time when lead time is critical. (5) Vendor-managed inventory (VMI) — supplier maintains stock at your premises.
- How does lead time affect working capital?
- Longer lead time = more inventory in the supply chain = more working capital tied up. If you need 100 units/day with 30-day lead time, you must hold 3,000 units in the pipeline. Reducing lead time to 10 days frees 2,000 units of inventory = 67% working capital reduction. This is why global companies invest heavily in supply chain lead time reduction — each day saved is cash freed.