"Inventory change refers to the change in the inventory of a product or commodity within a specific period of time. In the commercial field, inventory change is usually used to measure the inventory level of a company in the production and sales process, as well as the effect of inventory management. Changes in inventory can also reflect changes in market demand for a product or commodity.

Inventory changes can be divided into two types: positive changes and negative changes. A positive change indicates an increase in inventories, possibly because the business purchased more materials, produced more products, or received more inventory from suppliers. Negative change indicates a decrease in inventory, possibly due to more product being sold, or because some items have expired or become ineffective and are being eliminated.

Inventory changes can be measured in different ways. The most commonly used method is inventory turnover, which is the ratio between the number of products sold and the amount of inventory in a given time period. Inventory turnover rate can reflect the effect of enterprise inventory management and the degree of adaptation to market demand. A high inventory turnover rate usually means that the company has strong inventory management capabilities and is sensitive to market changes; a low inventory turnover rate may indicate inventory backlogs and poor sales.

Inventory changes have a great impact on businesses. Excessive inventory may lead to corporate capital being tied up, affecting cash flow; and too little inventory may lead to stock-outs, affecting the company's sales and reputation. Therefore, enterprises need to maintain an appropriate inventory level through scientific inventory management to adapt to market changes.

In addition, inventory changes also have an impact on supply chain management. Excessive inventory may mean that there is insufficient communication and coordination between the enterprise and suppliers, resulting in a decrease in the efficiency of the supply chain; while too little inventory may lead to interruption of the supply chain, unable to meet market demand.

To sum up, inventory changes are one of the important indicators of enterprises and markets, which can reflect the effect of enterprise inventory management and changes in market demand for products or commodities. Enterprises need to adjust production and sales strategies in time according to inventory changes to adapt to market changes, and maintain appropriate inventory levels through scientific inventory management. "