Levels of Data Flow Diagram (DFD)
Data Flow Diagram (DFD) uses hierarchy to maintain transparency thus multilevel Data Flow Diagram (DFD’s) can be created. Levels of Data Flow Diagram (DFD) are as follows:
0-level DFD
It is also known as a context diagram. It’s designed to be an abstraction view, showing the system as a single process with its relationship to external entities. It represents the entire system as a single bubble with input and output data indicated by incoming/outgoing arrows.
1-Level DFD
This level provides a more detailed view of the system by breaking down the major processes identified in the level 0 DFD into sub-processes. Each sub-process is depicted as a separate process on the level 1 DFD. The data flows and data stores associated with each sub-process are also shown. In 1-level DFD, the context diagram is decomposed into multiple bubbles/processes. In this level, we highlight the main functions of the system and breakdown the high-level process of 0-level DFD into subprocesses.
2-level DFD
This level provides an even more detailed view of the system by breaking down the sub-processes identified in the level 1 DFD into further sub-processes. Each sub-process is depicted as a separate process on the level 2 DFD. The data flows and data stores associated with each sub-process are also shown.
What is DFD(Data Flow Diagram)?
Data Flow Diagram (DFD) represents the flow of data within information systems. Data Flow Diagrams (DFD) provide a graphical representation of the data flow of a system that can be understood by both technical and non-technical users. The models enable software engineers, customers, and users to work together effectively during the analysis and specification of requirements.
Table of Content
- What is Data Flow Diagram (DFD)?
- Characteristics of Data Flow Diagram (DFD)
- Physical and Logical data flow diagrams (DFDs)
- Components of Data Flow Diagrams (DFD)
- Levels of Data Flow Diagram (DFD)
- Rules for Data Flow Diagram (DFD)
- Advantages of Data Flow Diagram (DFD)
- Disadvantages of Data Flow Diagram (DFD)
- How to Draw Data Flow Diagram?
- Conclusion
- Frequently Asked Questions (FAQs) related to Data Flow Diagram (DFD)