TS ISO/IEC 9126

TS ISO/IEC 9126 defines the core quality characteristics used to evaluate software products and provides guidance on how those characteristics can be applied when describing software quality. Rather than reducing quality to a single measure, the standard organises it around six largely non-overlapping characteristics, giving evaluators a shared framework for discussion and assessment.

The main dimensions of software quality

In general technical terms, this kind of model helps separate different aspects of quality such as functional behaviour, reliability, usability, efficiency, maintainability and portability. For software products, quality is not only about producing the right result; it also concerns consistent behaviour under different conditions, ease of maintenance, and the ability to adapt to other environments. That distinction is important in practice because stakeholders often need to compare products, document expectations, or plan evaluation activities using a common vocabulary.

Guidance and boundaries of the standard

The standard gives guidance on the use of quality characteristics for software quality evaluation, but it does not provide subcharacteristics, metrics, or a detailed evaluation method. In other words, it offers a conceptual structure rather than a complete measurement procedure. As a result, it serves as a foundation for more specific quality models and test or assessment approaches, while leaving the exact metrics and methods to be defined elsewhere.