The data flow chart represents the data path to solve the problem. At the same time, the main stages of processing and various data media used are specified.
The data flow chart includes:
A. A data symbol indicating the existence of data, or a medium used by data;
B, a processing symbol for processing data, or a machine function used in processing;
C. Streamline symbols representing data flow between several processing and/or data media;
D. read and write special symbols of data flow diagram.
There should be data symbols before and after processing symbols. A data flow chart begins and ends with data symbols. Improve the data flow chart, add all the added contents, and see the demand.