According to the Ito report announced by the Ministry of Economy, Trade and Industry in August 2014, it was pointed out that the issues of Japanese companies are not in asset turnover rates and financial leverage, but in terms of their ability to make earnings, compared to western companies. However, I believe that both accounts receivable turnover and inventory turnover are generally lower than those in Europe and the United States, among asset turnover rates, which is an issue for CCC (Cash Conversion Cycle) management.Inventory is an important management resource.Inventory is said to be a source of profit for business, at the same time, to cause loss. Especially in manufacturing, retail and wholesale business, management indicators are used to measure whether product inventory is being converted into sales efficiently.In general, the following two are used.1. Inventory turnover rateInventory turnover (times) = sales · cost of sales (annual) inventory amountThe inventory turnover rate is mainly used by executives for presentations for investors or shareholders.2. Inventory turnover periodInventory turnover period = inventory amount sales or cost of sales (monthly or daily)In fast-rotating industries such as foods, the daily sales are used for denominator and "days of stock days" is indicated.The inventory rotation period is practically used well.Annual average and month end stock are used for inventory, but the actual value for sales period / cost of sales is used for that period.It is enough to explain the past and current situation of inventory, but I think that it is inappropriate as an indicator for future decision-making internally. In other words, it is not inventory turnover as management accounting.I am convinced that inventory turnover days are an indicator that can assist decision-making to be shared by management, sales department in charge of operations, manufacturing, procurement, and logistics personnel as inventory-based management consultant.