the concept of ensuring inventory of beer (volume and sku's) is known as
Inventory The concept of inventory, stock or work-in-process has been extended from manufacturing systems to service businesses[1][2][3] and projects,[4][5] by generalizing the definition to be "all work within the process of production- all work that is or has occurred prior to the completion of production." In the context of a manufacturing production system, inventory refers to all work that has occurred - raw materials, partially finished products, finished products prior to sale and departure from the manufacturing system. In the context of services, inventory refers to all work done prior to sale, including partially process information.