In order to automate inventory and replenishment of the product in the warehouse, it is necessary to use software that will help you manage the warehouse and facilitate inventory. To do this, it is necessary to create a database of products, this database must contain such information as, 1. the amount of goods in stock 2. The minimum and maximum stock levels of each product. 3. Expiration dates and so on.
Such a system will be able to automatically control stock levels, and notify you in a timely manner that replenishment is needed.
You can also use a sales tracking and demand forecasting system to determine the optimal stock level for each product. It is also extremely important to conduct an inventory regularly, then you will always have accurate stock data. Well, you can always purchase ready-made warehouse accounting software.