Flow is not one of our topmost categories, and is not often named in business language, except according to things that travel along a flow.  We distinguish four types of flows in most enterprises:  flows of money, physical things, information (or data), and control.

Figure 10

Control flow tends to accompany, or direct the flow of other resources.  Flows begin and end at locations, which can be logical or physical, based on the type of resource traveling on the flow.  Flows trigger actions and functions, and are initiated by events, actions and functions, based on business rules.