What is DFD ?
DFD (Data Flow Diagram) are the most commonly used way of documenting the process of Current and required systems. DFD is a Graphical Representation of a System’s Data and How the Processes Transform Data. It is also Known a ‘Bubble Chart’. Unlike Flowchart, DFDs, do not give detailed description of Modules, but Generally describes a System’s data and how the data interact with the system.
Following are the Important Points Regarding DFD:-
- A DFD is a simple graphical Formalism that can be used to represent a system in terms of input data to the system, various processing carried out on these data and the output generated by the system.
- It is hierarchical graphical model that shows the different processing activities or functions that the system performs and the data interchange among these functions.
- It represents the flow of data in a system.
- It describes what data flows (logical) rather, than how they are processed.
- It enables the development of models of information domain and functional domain at the same time.
What is Full Form of DFD ?
Full Form of DFD :- DATA FLOW DIAGRAM
What are the Components of DFD ?
Components of DFD :
Following are the Components or Primitive Symbols used for Constructing DFD’s:
- Process :- A Function or Process or a Bubble is Represented using a circle. It transforms incoming data flows into outgoing data flows.
- External Entity :- A Rectangle Represents an External Entity. It defines a Source or destination of System data.
- Data Flows :- An arrow is used as a data flow symbol. It identifies data in motion. it represents data flow occurring between 2 processes or between external entity and a process in the direction of data flow arrow.
- Output :- Output box is used when a hard copy is produced and the user of the copies cannot be clearly specified or there are several users of the output.
- Data Store :- Open box represents data stores, Data store represents a logical file, a data structure or a physical file or disc. Each data store is connected to a process by means of a data flow symbols.