[confidantlake]

Doing inventory isn't just how counting how much of item A exists in a store for accounting purposes. More importantly it is making sure that the there enough items on a shelf for customers to purchase. This is known as "on shelf inventory".

An item in the backroom does not count towards the on shelf count. An item that is on a high shelf to be moved down as needed (overstock) does not count. And there isn't just a bit of overstock, most aisle the top shelf will be overstock. Also Items can get damaged, meat can expire ect. A customer can pick up an item decide he doesn't want to buy it, and throw it back on a random shelf.

The job involves going to an aisle, scanning the items on the shelf, and if the shelf count is not full either moving items down from overstock or from the back room.

[bluGill]

But once again you get that data from the register sales. there is a delay, but for the most part there are enough items on the shelf to last through the delay, or you would have sent someone to move items to the shelf anyway. Only when someone buys all of something is there are problem.