The Days Of Sales In Inventory Formula, or DOSII, is a key business metric used to measure the average number of days it takes for a company to sell its inventory. It is calculated by dividing the total inventory for a specific period by the average daily sales for that same period. This metric helps companies understand their liquidity and how quickly they can replace sold items with new products. By understanding DOSII, companies can develop strategies and plans to optimize their inventory and ensure they have enough stock to meet customer demand.