System structure diagram width

System structure diagram is a description method used by structured design method, also called structure diagram or control structure diagram. (Recommended Learning: PHPSTORM )

## This It means a hierarchical decomposition relationship, call relationship between modules, and modules The transfer relationship between data flow and control flow information. It is the main diagram tool for describing the physical structure of the system.

The system structure diagram reflects the calling relationship and hierarchical relationship of the modules in the system. Who calls whom has a sequence (timing) relationship. Therefore, the system structure diagram is not only different from the data flow diagram, but also Different from program flow chart.

The directed line segment in the system structure diagram indicates that the control of the program moves from the calling module to the called module when the call is made, and implies that control will be returned to the calling module when the call ends.

If a module has multiple subordinate modules, the left and right positions of these subordinate modules may be related to their calling order.

For example, in the transformation system structure diagram established based on the data flow diagram using structured design methods, all subordinate modules of the main module are logically input, centrally transformed, and logically output in order from left to right. When arranging words, the left and right positions are not irrelevant.

The system structure diagram is a graphical display of the overall design of the software system structure.

In the requirements analysis stage, from the perspective of system development, the system has been divided into hierarchical structures according to functions, so that each part can complete a simple function and maintain a certain relationship between each part. This is functional design.

In the design phase, the various parts are combined into a system based on this functional hierarchy.

Processing design: Determine the algorithms necessary to realize the functional requirements of the software system and evaluate the performance of the algorithms.

Determine the algorithms and inter-module control methods (performance design) necessary to meet the performance requirements of the software system. Determine the receiving and sending form of external signals.

The above is the detailed content of System structure diagram width. For more information, please follow other related articles on the PHP Chinese website!