Flow Oriented Modeling uses data flow diagrams, control flow specifications, and process specifications. Data flow diagrams depict the system as bubbles divided into processes with inputs and outputs between levels. Control flow specifications represent system behavior through state diagrams showing state transitions triggered by events. Process specifications describe each process through narrative text, algorithms, equations, or activity diagrams.

1. Flow Oriented Modeling
Data flow diagram
Control Flow Specification
Process Specification

2. Definition:
“It is based on structural analysis
technique. Structured analysis is a software
engineering technique that uses graphical
diagrams to develop and portray system
specifications that are easily understood by
users “

3. Guidelines:
• Depict the system as a single bubble in level 0.
• Carefully note Primary input and output.
• Always starts with level 0, level 1 and then level 2.
• In level 1 we divide our input into different processes and assign work
to each process.
• Label all elements with meaning names.
• Maintain Info conformity between levels.
• Refine one bubble at a time.

4. Data Flow Diagram
Example :level 0

5. Level 1

6. Level 2

7. Control Flow Specification:
• A short term for control specification is CSPEC.
• The CFD contains the same processes as the DFD, but shows control flow,
rather than data flow.
• It represents the behaviour of the system.
• The state diagram in CSPEC is a sequential specification of the behaviour.
• The state diagram includes states, transitions, events and activities.
• State diagram shows the transition from one state to another state if a
particular event has occurred.

8. State diagram for Safe Home security function

9. Process Specification:
• A short term for process specification is PSPEC.
• The process specification is used to describe all flow model processes.
• The content of process specification consists narrative text, Program
Design Language(PDL) of the process algorithm, mathematical
equations, tables or UML activity diagram.
• A process specification (PSPEC) can be used to specify the processing
details implied by a bubble within a DFD.

10. Process Specification(Written Description):