Structural Quality Assurance is the process of evaluating the non-functional attributes of a software system, particularly focusing on how well it is structured internally. Unlike external quality (which deals with factors like usability, functionality, and reliability perceived by users), structural quality looks into the architecture, code, and components of the software.

Structural quality assurance aims to ensure that the software:

• Is maintainable.
• Can be efficiently scaled.
• Is robust and does not have vulnerabilities.
• Has an architecture that is both coherent and cohesive. To understand it better, think of a building: if the foundation, materials, and architectural design are sound, the building will be more durable and safe.

Examples of structural QA

Avoiding Deep Nesting

A common structural problem in PHP is deeply nested code, which makes it difficult to read and maintain.