Use a normal-approximation model to translate demand and lead-time variation into a buffer quantity for planning review.
FIELD GUIDE / INVENTORY
Choose a cycle service level and enter the standard deviation of daily demand.
Enter average lead time; optionally add average daily demand and lead-time standard deviation.
Round the result according to real order multiples, then validate against actual service performance.
USE CASES
MODEL BASIS
SHIFT QUESTIONS
Leave lead-time standard deviation at zero; the calculation then uses demand variation during average lead time.
No. Select service by shortage cost, customer promise, margin, criticality, and working-capital policy.
Operationally, buffers are usually rounded up to whole units or an approved order multiple after review.