flow oriented modeling

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):