Modularity

Modularity is the degree to which a system or program is composed of discrete, independent modules, such that a change to one has minimal impact on the others. It is a quality attribute and, per ISO/IEC 25010, a sub-characteristic of maintainability. A highly modular system is easier to understand, change, and extend because the effects of a change stay local to the module being changed.

Modularity is closely tied to coupling and cohesion. A system achieves high modularity by keeping coupling between modules low and cohesion within each module high, so that responsibilities are grouped sensibly and dependencies between them are minimized. Modular design is the practice of deliberately pursuing this structure.

References

• ISO/IEC (2023). ISO/IEC 25010:2023 — Systems and software Quality Requirements and Evaluation (SQuaRE) — Quality model.