Stock cover days

Stock cover days is how many days of trading your current stock will last at your recent rate of use: divide the quantity you hold of an item by its average daily usage. Two days of cover on a fast-moving line is a stockout waiting for one late delivery; forty days on a slow one is cash sitting in a cold room. It is a per-item number, not a warehouse number — an average across a store hides both problems at once, which is the usual reason neither gets fixed.

For perishables the figure has a hard ceiling: cover beyond shelf life is not cover, it is future wastage with a date on it. Reorder points set once and never revisited are how a kitchen ends up holding eleven days of something that keeps for six.

The number is also the honest input to a purchasing conversation. Ordering by habit produces both stockouts and dead cash in the same week, and the only way to see which lines are which is to hold each one's cover against its usage rather than against a feeling about how fast it moves.