Modularity
Modularity is the degree to which a software system is composed of independent, cohesive components with minimal dependencies between them.
“The degree to which a system is composed of discrete components such that a change to one component has minimal impact on other components.”
(Definition reproduced from the ISTQB Glossary. Copyright belongs to ISTQB.)
View the complete ISTQB GlossaryWhat is Modularity?
A modular design simplifies development, testing, maintenance, and reuse by reducing interactions between unrelated parts of the system.
Independent components: Modules perform well-defined responsibilities.
Low coupling: Modules interact through clear interfaces.
Testing benefit: Independent modules are easier to isolate and verify.
Real World Example
A regulated product team is preparing a release where Modularity appears in reviews, test design conversations, or defect triage rather than as an isolated glossary word.
The risk is that the team treats Modularity as interchangeable with nearby ISTQB terms. That makes test scope blurry and can lead to weak evidence for the release decision.
The tester anchors the discussion in the official definition, asks where the concept appears in the product, and designs examples that show the difference between Modularity and similar ideas.
The page becomes useful in practice because Modularity is connected to a specific testing decision, not memorized as a detached definition.
Practice Questions
Question 1
Which statement BEST describes Modularity in the context of ISTQB terminology?
Question 2
A tester needs to explain Modularity to a non‑technical stakeholder. Which approach is MOST appropriate?
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