Architecture Diagrams
Data Flow Diagram
- Graphical representation of system’s flow of information
- How data is processed by a system in terms of inputs , outputs and where that information is stored.
Data Flow Diagram symbols are standardized notations
- External entity
- Represented in
rectangles with a short-text labels haveing the Domain o
- Outside system that sends or receives data
- Might be an outside organization or person, a computer system or a business system
- Process
- Represented in
circle with a short-text labels have Process action
- Any process that changes the data, producing an output
- Data store
- Represented in
Data rectagles (with right border open) with a short-text labels having what Model is stored
- Files or repositories that hold information for later use
- Data flow
- Represented in
Arrow with a short-text labels having what data is flowing
- route that data takes between the external entities, processes and data stores
DFD rules and tips
- Each process should have at least one input and an output.
- Each data store should have at least one data flow in and one data flow out.
- Data stored in a system must go through a process.
- All processes in a DFD go to another process or a data store.
Levels
Level 0
- Shows Boundry of the System
- It’s called
Context Diagram