Data Flow Diagram - Types of DFD


Physical and Logical DFDs

There are two types of data flow diagrams, namely physical data flow diagrams and logical data flow diagrams and it is important to distinguish clearly between the two:

Physical Data Flow Diagrams

An implementation-dependent view of the current system, showing what tasks are carried out and how they are performed. Physical characteristics can include:

Names of people
Form and document names or numbers
Names of departments
Master and transaction files
Equipment and devices used
Locations
Names of procedures

Logical Data Flow Diagrams

 

An implementation-independent view of the a system, focusing on the flow of data between processes without regard for the specific devices, storage locations or people in the system. The physical characteristics listed above for physical data flow diagrams will not be specified.

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