of metrics associated with this concept. For data and control flow coupling: di: number of input data parameters ci: number of input control parameters do: number of output data parameters co: number of output control parameters For global coupling: gd: number of global variables used as data gc: number of global variables used as control For environmental coupling: w: number of modules called (fan-out) r: number of modules calling the module under consideration (fan-in) Coupling(C) makes the value larger the more coupled the module is. This number ranges from approximately 0.67 (low coupling) to 1.0 (highly coupled) For example, if a module has only a single input and output data parameter If a module has 5 input and output data parameters, an equal number of control parameters, and accesses 10 items of global data, with a fan-in of 3 and a fan-out of 4, See also Cohesion (computer science) Connascence (computer science) Coupling (physics) Dead code elimination Dependency hell Efferent coupling Inversion of control List of object-oriented programming terms Loose coupling Make (software) Static code analysis References Further reading Programming principles Object-oriented programming Software architecture Software metrics