The UAF Resource Flow viewpoint enables you to model the Functions that Resources (such as Systems) perform, and the resources (such as Data, and so on) that are sent between Functions. A Function transforms a Resource into a different Resource.
You may also model the Resource that PerformsInContext the Function. This relationship is the ResourceRole – the Role the Resource performs is dictated by the Function it performs.
You may model a Resource Flow as a ‘Context’ diagram (showing a high-level Function and the external Functions it communicates with – and then create a child ‘Decomposition’ Resource Connectivity diagram to delineate how Functions interact.
There is no implied flow to the diagram – you should concentrate on what Function sends what Resources to another Function – not which comes first, second, third, and so on. You can draw the Functions in a circle, for example, and have the same information conveyed.