Software engineering base schema (Chapter IV system design - oriented system design process)
1, structure design method
2, the system configuration module of FIG.
3, the system configuration diagram transform type
4, the system configuration diagram of transactional
5, transformation analysis
Example 1: FIG converting the DFD / data flow diagram of the software / control structure of FIG. (Bad, look mode)
Example 2: converting the control data flow graph following the structure of FIG.
Transform Analysis Notes
After the selection order when ① modular design, all modules must be a direct subordinate modules are designed to complete before turning lower module design another module.
② In the design of the lower module, the coupling should be considered and cohesion existing module, to improve the quality of the initial structure of FIG.
③ using the "black box" technique: In the design of this module, the first module of all the lower block is defined as "black box", when using them in the design, not to consider its internal structure and implementation. In this step-defined "black box", the next step will be to design and processing them. In this way, it will lead to more "black box." Finally, all of the "black box" of the content and structure should be completely determined.
④ When dividing module, a module is directly subordinate modules generally about 5. If more than 10 direct reports module, you can set up intermediate level.
⑤ If the following happens, stop functional decomposition module:
- When the module can not be subdivided into distinct sub-tasks;
- When broken down into modules or subroutines library provided by the user;
- When the module input interface information transmitted / output device;
- When the module is not appropriate to decompose too hours.
6, Transaction Analysis
1) Overview
2) Transaction analysis
3) Examples: Please DFD in the figure is converted into a software configuration of FIG.
7, the hybrid structure analysis
Transform analysis is the main method of software system architecture design. Typically, a large software system is a hybrid-type structure and structural conversion transactional structure. So, we usually use to transform the main analysis, transaction analysis, supplemented by way of software design.
8, structural design component
