All data-driven managers understand intuitively that clear visibility into inventory will help them make better decisions. With traditional methods of taking inventory counts, accuracy was desired but seldom achieved.
Given the size of large stores and warehouses, the best managed retail operations were able to take a complete inventory perhaps once or twice a year.
Even that was a monumental exercise without guaranteed accuracy, because inventory continues to change even as it's being counted.
As often happens with manual stock-taking, some items may be counted twice while others are missed entirely…