the store does know, or can figure out if they really wanted to.
every vendor is assigned some shelf space and has some restocking day (like every morning for bread) when the shelves are expected to be 100% full.
then they have purchases data from point of sale terminals/online orders.
every vendor is assigned some shelf space and has some restocking day (like every morning for bread) when the shelves are expected to be 100% full. then they have purchases data from point of sale terminals/online orders.
the problem becomes A minus B