The DFD (Data Flow Diagram) and Flowchart are presented in a similar manner which makes it confusing, as both constructed with the similar symbols. Though, there is a big difference between the DFD and Flowchart because the DFD is used to specifies the flow of data in the design of the system while flowchart depicts the flow of control of a system.
A flowchart is an elementary approach for structuring an explication of a problem which can be implemented in the various branch of knowledge. DFD (Data Flow Diagram) is evolved later and mainly used in planning and designing of the software.
Content: DFD Vs Flowchart
|Basis for comparison||DFD||Flowchart|
|Basic||Shows the flow of the data.||Steps to complete a process or solution of the problem.|
|Illustrates the flow of||Data||Control|
|Execution of the process||Sequential||Sequential and can be parallel too.|
|Input/Output||Input/output entities can exist.||Does not contain input/output|
Definition of DFD
The DFD (Data Flow Diagram) is a design method and structured analysis, which represents the relationship among the various components in a system or software. The DFDs are very useful in modelling the high-level aspects of a system through transforming input data into output with the help of a series of function in an order.
A data flow diagram contains three major elements – entities, processes, data stores, and data flows.
- Entity: The entities in the DFD is a source or destination of the data where the source does not reside within the system. The source is an entity which offers the data to the system while the entities accepts the data from the system will be known as a sink. A rectangle is used to represent an entity.
- Process: The work of process is to perform computations, leading business based on the rules, making decisions, transforming data, and so on. A circle is used to represent a process and it contains a process name and process number.
- Data Store: It is a repository for storing the data for the subsequent retrieval by the same or other processes. It is drawn as a rectangle with two parts one is closed another one is open.
- Data Flow: The arrows in a DFD shows the data flow. Data flow is the interaction between different components of DFD of a system such as entities, process and data stores.
Definition of Flowchart
The Flowchart is more general in a sense as it can be used in various disciplines and universally recognized. It defines the steps in the graphical form of a solution to a problem. We can say that a flowchart is earlier approach than DFD for designing and structuring the solution to a problem. It can also be used for describing the steps of a program. Our human mind grasps the images in a faster manner rather verbally. So, these methods are evolved as a positive result. Similar to DFD, the flowchart also has elements such as a rectangle, circle, arrow lines, ellipse and so on. It signifies the sequence, decision points, starting and stopping etcetera.
Here is the list of the components of the flowchart.
- Rounded rectangle: It is used to show the beginning and the ending of the flowchart.
- Rectangle: A rectangle symbol represents the process.
- Diamond: Any conditional statement is written in the diamond symbol where any question involving a binary answer can be asked.
- Circle: The circle works as the connector and to connect to the remaining part of the flowchart so the designer could continue it at a different place without creating any previous chart.
- Arrow: Represents how the data is flown within the system.
- Parallelogram: It is used to show the input given to the system and output generated by the system.
Key Differences Between DFD and Flowchart
- The DFD is the structure or design of the system which represents the data flow in the system. In contrast, a flowchart is quite similar to DFD but it interprets the flow of control of the system.
- A flowchart processes each step one after the other while in DFD the two processes can be executed parallelly.
- A DFD diagram can have input/output entities. As against, the flowchart cannot have any input from or output to an external source.
- The flowchart gives a representation of the system at a higher level. On the contrary, DFD provides a lower level view.
The article is intended to clarify the difference between the DFD and flowchart where in flowchart the sequence of the process performed is emphasized while this is not the case in DFD. The DFD process data in parallel but in flowchart, it is not workable.