Factory warehouses and traders' inventories. Implicit inventory refers to the fact that there has been a transaction between manufacturers and distributors, but the products have been pressured by distributors, and there has always been a good financial record on the books, but the goods have not really been sold, stuck in the channels, blocking the channels, which is essentially inventory. Factory warehouse and trader inventory are invisible inventory systems of soda enterprises. Soda industry refers to the basic inorganic chemical industry with soda as its main product.