What is fan-in and fan out? __software

What is fan-into and fan out.

In software design, the concept of fan-and fan-out refers to the hierarchical invocation between application modules.

According to the structured design approach, an application is composed of several modules with relatively independent functions.

Fan in: Refers to the number of parent modules that call the module directly. Fan into large indicates that the module has a high reuse program.
Fan-out: Refers to the number of subordinate modules that are called directly by the module. Fan out large indicates the complexity of the module, need to control and coordinate too many subordinate modules, but the fan out too small (such as always 1) is not good. Fan out too large is generally due to the lack of intermediate level, should be appropriate to increase the middle level of the module. The fan out too hours can further decompose the subordinate module into several sub function modules, or merge into its superior module.


Design good software structure, usually the top fan out relatively large, the middle fan out small, the bottom module has large fan into.


Other answer fan in: the input of a gate is defined as the number of inputs to the door.
Fan out: A word used to describe the driving power
It is more appropriate to say that a description of the load condition is described