Software Engineering basics - Software Quality Assessment Methods (SQALE)

Software Quality Assessment methods aim to systematically evaluate and manage software quality throughout the development lifecycle. One prominent approach is SQALE (Software Quality Assessment based on Lifecycle Expectations), which focuses on measuring and managing technical debt using objective, quantifiable metrics.

SQALE is based on a quality model structured as a tree, where high-level quality characteristics (such as maintainability or reliability) are decomposed into sub-characteristics and concrete requirements. Each requirement is associated with specific coding rules and measurable violations, enabling automated analysis.

A central concept in SQALE is technical debt expressed in time units, representing the estimated effort required to fix quality issues. This allows organizations to treat quality problems as financial and scheduling decisions rather than abstract concerns. It also enables prioritization of refactoring efforts based on cost and impact.

SQALE integrates well with static code analysis tools, continuous integration pipelines, and quality dashboards. It supports both preventive actions (avoiding new debt) and corrective actions (paying down existing debt). This makes it suitable for agile and DevOps environments.

By aligning quality assessment with business objectives, SQALE helps teams make informed trade-offs between speed and quality. Its structured and lifecycle-oriented approach makes it particularly useful for large enterprise systems and regulated environments.