What is inventory days of supply?

Days of supply is how long current stock will last at the current rate of sale: units on hand divided by average daily units sold. It converts a quantity into a time, which is the form a buying decision actually needs, and it is directly comparable to supplier lead time.

Comparing days of supply to lead time is the fastest stockout check there is. Thirty days of stock against a forty-five day lead time means the stockout is already scheduled.

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