Once you have your goals, you need to track your performance against them, which requires collecting and analyzing data on your inventory processes and outcomes. To measure your inventory management speed, you should look at the inventory turnover ratio, days sales of inventory (DSI), fill rate, and lead time. The inventory turnover ratio shows how many times you sell and replace your inventory in a given period, with a higher ratio indicating faster inventory movement and lower holding costs. DSI indicates how many days it takes to sell your average inventory level, with a lower DSI suggesting faster inventory turnover and higher liquidity. The fill rate reveals the percentage of customer orders that you can fulfill from your available inventory, with a higher fill rate indicating higher service level and customer satisfaction. Lastly, lead time indicates the time from placing an order to receiving the goods, with shorter lead time indicating faster replenishment and lower ordering costs.