Flow oriented Modeling - Creating a Control Flow Diagram and The Control Specification

Flow models focus on the flow of data objects as they are transformed by processing functions. There are applications which are driven by events rather than data and produce information that is controlled and process information keeping in mind the time and performance. In such situations, control flow diagrams comes into picture along with data flow modeling.

There are some guidelines to select potential events for a control flow diagram:
- all sensors that are read by the software are listed.
- all interrupt conditions are listed.
- all switches actuated by operator are listed.
- all data conditions are listed.
- all control items are reviewed.
- all states that describe the behavior of a system are listed.
- all transitions between states are defined.
- all possible omissions should be kept in focus.

The Control Specification contains a state diagram which is sequential specification of behavior. It contains a program activation table which is a combinatorial specification of behavior. Control specification does not give any information about the inner working of the processes activated as a result of this behavior.