Data Flow chart system flow chart program system structure chart differences and links

1. Data Flow Diagram)

Adhere to DFD, which expresses the system's logical functions in graphical form from the perspective of data transmission and processing. The logical flow of data within the system and the logical Exchange Process, is the main expression tool of the structured system analysis method and a graphical amplification used to represent the software model. It is a transformation that depicts information flows and data flows from input to output.

Basic elements of a data flow diagram:

Example:

2. system flowchart)

Traditional tools that describe the physical model of the system. His basic idea is to use graphical symbols to depict every part of the system concept in the form of a black box, including programs, files, databases, tables, and human processes, it expresses the flow of information between parts, rather than the control process for processing information.

Example:

3. program flowchart

Standard symbol of the program flowchart

Example:

4. Program System Structure

Example:

• Data Flow Chart: The process of response transmission. It is mainly used for business analysis and is used for detailed design without considering the time sequence relationship. A directed line segment represents a data stream.

• System flowchart: response body framework

• Program flowchart: The process logic describes the control flow in the program, that is, the execution sequence and execution sequence of the program, A directed line segment indicates that the control flow goes from one processing to the next processing.

• System Structure Diagram of the program: reflects the call relationships and hierarchies of modules in the system. A directed line segment indicates that the program control is called from the call module together, and the control is returned to the call module when the call ends.

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Data Flow chart system flow chart program system structure chart differences and links