basic elements of the streaming diagram:
Why use a streaming diagram?
because flow graphs represent the flow and processing of class data in the system. The streaming diagram is a tool used in structured analysis, and it is a functional model because it only reflects the logical functions that the system must complete. and users and developers to communicate with the use of data flow diagram to communicate with a clearer understanding of the user's needs and requirements.
so let's use the streaming chart now! PrinciplesDivide the picture flow chart into three categories: shape, structure, and relationship. refers to the flow diagram for the whole can be clear, distinct levels. The figure alien is decomposed inward and from top to bottom. The parent and child graphs are balanced, the parent can be decomposed into sub-graphs, the sub-graphs can be merged into the parent graph, and their data is conserved, and there are in-out. for the basic elements of the process to be able to contributors simple, processing details hidden. Data dictionary :
Record and interpret terms in the flow graph.
each symbol in the flow graph can be written into a dictionary.
a data dictionary can be used to describe any element in a DFD diagram.
Summary: DFD is an important tool for users to communicate with developers when conducting demand analysis. Use it properly and do more with less.
Soft test--flow chart
