What this calculator does
Lead-time demand is average daily demand × supplier lead time. It isolates expected demand, which is one part of a reorder point.
When to use it
Use it to validate replenishment exposure and distinguish demand planning from service-level or safety-stock policy.
Inputs and formula
Average daily demand should reflect the item’s forecast or historical issue pattern; lead time includes supplier, transport, receiving, and inspection delays as applicable.
Worked example and interpretation
Three units per day and 21 days of lead time require 63 units on average before uncertainty protection is added.
Practical notes and limitations
Intermittent spare demand does not always behave like a stable daily average. For highly critical low-volume spares, use scenario review as well as formula output.