When the system is divided into several modules, the relationship between the modules is called the inter-block relationship, and the implementation logic inside the module belongs to the internal subsystem of the module. For the module division of software, it is necessary to follow some basic principles. The system designed according to the basic principle for module division has strong reliability, stable system, and is convenient for maintenance and upgrade.
Design modules often pay attention to many problems. A good module partitioning scheme can bring a lot of convenience to system development, improve the development efficiency of the whole system, and it will reduce the maintenance difficulty of the system later. Conversely, if the module is not properly classified, it will not only bring convenience, but also affect the development of the program.
When classifying software modules, the first criterion to be followed is to ensure the independence of each module. The so-called module independence, that is, the links between different modules are as few as possible, and the public variables and data are reduced as much as possible. structure. Each module is logically independent as much as possible, functionally complete and single, and there is not much coupling between the data and other modules.
Module independence guarantees the singularity of each module's functions, and the uniformity of the interfaces can fully reduce the coupling between modules. When the software module is divided, if there are too many links between the modules, the poor module independence may cause the system structure to be confused, and the hierarchical division is not clear. The resulting requirements are related to multiple modules, which seriously affects system design.