Calculator Inputs
The page uses a single stacked content flow, while the calculator fields respond in 3, 2, and 1 columns by screen size.
Example Data Table
| Parameter | Example Value | Unit | Why It Matters |
|---|---|---|---|
| Annual Demand | 120,000 | Units | Defines the flow volume across the network. |
| Opened Facilities | 3 | Count | Controls fixed cost, service reach, and resilience. |
| Capacity Per Facility | 50,000 | Units/year | Determines available throughput per site. |
| Average Outbound Distance | 180 | km | Drives outbound transport spending. |
| Transport Rate | 0.042 | $ per unit-km | Converts flow and distance into freight cost. |
| Inventory Carry Rate | 18 | %/year | Captures storage, capital, and obsolescence burden. |
| Handling Cost | 1.20 | $ per unit | Reflects touchpoints inside the warehouse network. |
| Late Orders | 40 | Orders/year | Measures service leakage and penalty exposure. |
| Safety Stock Days | 8 | Days | Adds inventory to protect service performance. |
| Target Cost Per Unit | 14.50 | $ | Benchmarks the design against a planning goal. |
Formula Used
Daily Demand = Annual Demand ÷ 365
Average Inventory = Cycle Stock + Pipeline Stock + Safety Stock
Cycle Stock = (Average Order Quantity ÷ 2) × Facilities
Pipeline Stock = Daily Demand × Lead Time Days
Safety Stock = Daily Demand × Safety Stock Days × √Facilities
Outbound Transport Cost = Annual Demand × Average Distance × Transport Rate
Inventory Carrying Cost = Average Inventory × Unit Value × Carry Rate
Capacity Utilization = Annual Demand ÷ (Facilities × Capacity Per Facility) × 100
Service Level = [1 − (Late Orders ÷ Orders Per Year)] × 100
Total Cost = Fixed + Outbound + Inbound + Handling + Carrying + Coordination + Penalty + Carbon
Network Score = Weighted average of cost, service, utilization, and resilience indices
The nearby facility comparison estimates alternative average distance using a square-root rule. It is a planning shortcut, not a full optimization solver.
How to Use This Calculator
- Enter annual demand and the number of facilities you plan to open.
- Add per-facility capacity to test whether the proposed network can absorb the flow.
- Fill in outbound distance, freight rate, inbound cost, and handling cost.
- Enter unit value, carrying rate, lead time, and safety stock days for inventory effects.
- Add late-order assumptions and penalty values to reflect service failure costs.
- Set coordination overhead, shipment load, and carbon cost for broader network impact.
- Choose target unit cost and target utilization for benchmarking.
- Adjust score weights to prioritize cost, service, utilization, or resilience.
- Click the calculate button to view results above the form.
- Use the CSV or PDF buttons to export the current result set.
FAQs
1) What does this calculator optimize?
It helps compare logistics tradeoffs among facility count, transport distance, inventory burden, service penalties, and utilization. It does not replace a full mixed-integer network optimization model.
2) Why does facility count change total cost?
More facilities usually reduce outbound distance and may improve service. They also increase fixed cost, coordination effort, and decentralized safety stock. The lowest cost design often sits between those competing effects.
3) What is the network score?
The score blends cost, service, utilization, and resilience into one weighted measure. It is useful for screening scenarios quickly when leadership wants one summarized planning indicator.
4) How should I choose the target cost per unit?
Use a strategic benchmark from your budget, previous year, bid pricing, or contract target. The score improves when the modeled unit cost meets or beats that reference.
5) Why is safety stock multiplied by the square root of facilities?
That rule approximates the common risk-pooling effect in decentralized inventory systems. It is a practical engineering shortcut for early design work and quick scenario testing.
6) Can I use this for inbound and outbound studies together?
Yes. Outbound freight is modeled from distance and unit-kilometer rate, while inbound cost is entered separately as a unit cost. That structure keeps the model easy to maintain.
7) What does low utilization mean here?
Low utilization suggests extra capacity is being paid for without being used. That may be intentional for resilience, but it can also signal too many facilities or oversized sites.
8) Is the nearby facility comparison exact?
No. It is a quick planning approximation that adjusts distance and service assumptions around the chosen facility count. Use a detailed optimization study before making final capital commitments.