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Supplier Lead Time Cost Calculator — Lead Time Reduction ROI

Calculate the true cost of long supplier lead times. Safety stock carrying cost, emergency freight, and lost sales — and find the ROI of negotiating shorter lead times.

Quick answer: Every 30-day reduction in supplier lead time reduces safety stock by 40–60% for that item. On $2M inventory at 25% carrying cost: 30-day lead time reduction saves $20,000–$30,000/year in carrying cost alone.

⏳ Supplier Lead Time Cost Calculator

Annual Carrying Cost Saving
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Safety Stock Reduction
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Total Inventory Reduction
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How to Use This Calculator

  1. Enter demand and variability data — average daily demand and standard deviation for this supplier's SKUs.
  2. Enter current and target lead times — current lead time from your PO history; target from supplier negotiation or alternative sourcing.
  3. Multiply by number of SKUs — the saving applies to every SKU from this supplier — multiply for full programme value.

Worked Example

120 units/day demand, σ30, 45→21 day LT, $42 unit cost, 25% holding, 95% SL, 1 SKU.

  1. Current SS: 1.65 × 30 × √45 = 332 units
  2. Target SS: 1.65 × 30 × √21 = 227 units
  3. SS reduction: 105 units
  4. Cycle stock reduction: (45−21) × 120 / 2 = 1,440 units
  5. Total inv reduction: 1,545 units × $42 = $64,890
  6. Annual saving: $16,223

A 24-day lead time reduction saves $16,223/year in carrying cost — before accounting for reduced emergency freight and improved fill rates. For 10 SKUs from this supplier: $162,230/year.

Frequently Asked Questions

Consignment stock at the supplier (supplier holds safety stock for you), vendor-managed inventory (VMI), blanket purchase orders with scheduled releases, prepayment incentives, or dual-sourcing with a near-shore supplier. Show suppliers the business case — faster lead times often win you more volume commitments.

Production scheduling (supplier batch sizes), raw material availability, quality inspection time, customs/export documentation for international suppliers, and ocean transit time. Map each component separately — you may be able to reduce inspection or documentation time without changing production schedules.