700 units is the example result. Read it using the units and relationship stated below.
Purchase Order Lead Time Demand uses lead time (days), daily requirement.
Balancing availability against cash tied up in stock
For purchase order lead time demand, the relationship is Demand during lead time (units) = replenishment lead time (days) × average daily requirement. This estimates demand coverage, not the supplier delivery date. The amount depends on the supplied lead time (days), daily requirement, rather than a live market price or a value imported from another record. An inventory decision must connect demand, lead time and the cost of holding goods. Buying more can reduce ordering frequency but ties up cash and storage. A stock ratio is useful only when its demand period is clear.
What the model includes
Demand during lead time (units) = replenishment lead time (days) × average daily requirement. This estimates demand coverage, not the supplier delivery date. Use purchase and sales records from a comparable period. Separate regular consumption from a promotion or one-off order; otherwise a reorder assumption can carry a temporary spike into the next purchasing cycle. Check supplier pack sizes, minimum quantities and delivery reliability before turning a calculated amount into an order. The model does not measure deterioration, seasonality or the cost of a stockout unless those inputs are present.
Example with the supplied inputs
Lead time (days): 14; Daily requirement: 50. Result: 700 units. The values are illustrative.
Compare one changed input
Lead time (days) changes from 14 to 15.4. The result becomes 770 units. All other inputs remain fixed.
Calculation rule
Demand during lead time (units) = replenishment lead time (days) × average daily requirement. This estimates demand coverage, not the supplier delivery date.
Inputs and output
| Input | Example value | Entry convention |
|---|---|---|
| Lead time (days) | 14 | Use the duration unit stated in lead time (days). A time period is not interchangeable with a currency amount or a count of events. |
| Daily requirement | 50 | Use the source quantity represented by daily requirement. Keep the counted population fixed and avoid mixing a unit value with a period total. |
Output: 700 units is the example result. Read it using the units and relationship stated below. Unit: units.
How to use the page
Collect the inputs
Gather Lead time (days), Daily requirement. Use one period and the units shown in the form.
Run the calculation
Enter the values and select the action. The calculation rule above explains how the inputs produce the result.
Compare a scenario
Change Lead time (days) on its own, keeping the other inputs fixed. Read both results before changing another assumption.
Worked example
With the example inputs listed above, the result is 700 units.
Change Lead time (days) from 14 to 15.4 while keeping every other value fixed. The result becomes 770 units. This comparison isolates that input; it does not forecast how other variables will respond.
Check the stated formula, units and limits before using the result in a decision.
Keep the displayed formula, input units and model scope with the result. Corrections or questions can be sent through the request section on this page.
Content updated: October 11, 2026