Inventory management comprises functionalities and methods for managing and finding identical and differing warehouse inventory items. Warehouse stocks can be managed at storage locations, on resources (e.g. on forklifts, order picking trolleys, storage and retrieval machines) or on transport units (e.g. trucks, railway wagons). In order to differentiate stocks from each other, the WMS uses stock-differentiating properties that enable the stocks to be clearly differentiated, e.g. material, batch, client, country of origin, customer order, or project. Another important stock-differentiating property is the stock type. Based on the stock type, a differentiation is made as to whether a stock is part of e.g. the stock readily available, the locked stock, the quality inspection stock or the customs stock. Furthermore, it is possible to determine whether the stock is in transport to or already at the storage location. If the stock-differentiating properties of two stocks are identical, the stocks quantities can be merged (e.g. with addition to existing stock at one storage location). Otherwise, the stocks can clearly be differentiated from each other based on their stock-differentiating properties. Stocks with different stock-differentiating properties can also be grouped together on a project-specific basis. However, the properties for the new stock then have to be defined. Using the methods of stock determination, stocks can be selected for specific warehouse activities based on stock types and clients. Stock determination can be done separately for each material. A special case of inventory management applies for material that is requested in custom base quantity units (e.g. lengths, volumes, surface). Here, a classification into residual quantities and cut parts is done even before processing. Examples are wood, cable, and glass cuts. The cut material is therefore called cut. Differing from this, the term filling is used for liquids and bulk material. The resulting requirements for inventory management and retrieval strategies must be taken into consideration.