What must you define to ensure that the production flow occurs only in physically connected tanks?

To ensure that the production flow occurs only in physically connected tanks, the resource network must be defined. A resource network in SAP refers to the arrangement of resources, such as machinery or storage tanks, that are available for production processes. By defining this network appropriately, you establish the physical and logical connections between various production resources.

In the context of connected tanks, defining a resource network allows the system to recognize which tanks can be involved in the production flow based on their physical connectivity. This means that any production order or process associated with these tanks will respect their physical layout and limitations, ensuring that only compatible and connected tanks are considered for the production cycle.

While options like operation network and work center hierarchy pertain to how operations and work centers are organized and managed within SAP, they do not specifically control the physical connectivity required for production processes between tanks. The setup matrix focuses on the preparation requirements between different resources but does not address the established physical connections necessary for flow. Therefore, defining the resource network is key to managing the flow correctly in contexts where physical connectivity is crucial.