Software Architect's Handbook

Reducing coupling

Coupling refers to how dependent different modules are on each other. Designs should seek loose coupling, such that different modules are independent of each other or almost independent. If it becomes necessary to make changes to a highly coupled module, it will be more likely that other modules will be affected and therefore also require changes. Loose coupling reduces complexity and enables a number of different quality attributes, including maintainability. Loose coupling often correlates to high cohesion.