Sales Velocity + Days of Cover: turning movement into urgency
Velocity and days of cover are the bridge between “we have inventory” and “we are safe or unsafe.” Franz must understand these slowly because this is where many restock mistakes are born.
Velocity asks
How many units does this product sell per day?
Days of cover asks
How many days will current usable inventory last at that pace?
Why it matters
Same inventory count, different sales velocity, completely different risk.
Velocity windows
7-day velocity
Good for catching recent movement, promotions, sudden drops, and listing changes. Dangerous if treated as long-term truth.
30-day velocity
Usually the core planning window because it is recent but less jumpy.
60/90-day velocity
Useful for seasonality, slower products, and smoothing unusual weeks.
Manual judgment
If velocity changed because of a stockout, sale, listing suppression, MAP pressure, or buy box loss, the math may need manual adjustment.
Days of cover example
If available inventory is 250 units and velocity is 10 units/day, days of cover is 25 days. If lead time is 20 days, that looks tight. If velocity is only 2 units/day, the same 250 units is 125 days of cover and may not need a reorder.