Coupling and Cohesion

This research examines the structural complexity of software, and specifically the potential interaction of the two most important structural complexities: coupling and cohesion.Coupling and Cohesion are the two terms which very frequently occur together. Together they talk about the quality a module should have. Coupling talks about the interdependencies between the various modules while cohesion describes how related functions within a module are. Low cohesion implies that a given module performs tasks which are not very related to each other and hence can create problems as the module becomes large.Thus, Cohesion represents how tightly bound the internal elements of a module are to on another. Coupling is the nature of degree of independence between modules. Its measures by the no. of interconnection b/w modules.High cohesion and low coupling is main criteria for good s/w design. The theory-driven approach taken in this research considers both the task complexity model and cognition and lends significant support to the developed model for software complexity. Furthermore, examination of the task complexity model steers this paper towards considering complexity in the holistic sense of an entire program, rather than of a single program unit, as is conventionally done. Finally, it is intended that by focusing software measurement on coupling and cohesion, research can more fruitfully aid both the practice and software complexity management. Keywords-Software complexity, software structure, task complexity, coupling, cohesion.