Currently, all inner state of "flow" displayed inside process design. I think we can improve its encapsulation.
For example:
1. Create a flow, add actions inside the flow.
2. Set values for actions input/output properties which should encapsulated inside flow in flow design.
3. For flow itself, user can add input/output properties.
4. For action's input/output which user want "export" to outside, user can "link" the input/output to flow's input/output.
5. In process design, flow's usage is as simple as action.