Software Quality Assurance (SQA): Building Quality into the Software Development Process
Explore the principles and practices of software quality assurance (SQA). This guide defines software quality characteristics, explains the difference between SQA and quality control, and discusses key SQA activities for building reliable, efficient, and user-friendly software systems.
Software Quality Assurance (SQA)
Introduction to Software Quality
Software quality refers to a set of characteristics (correctness, reliability, efficiency, maintainability, usability, portability, integrity, reusability, and interoperability) that determine how well software meets user needs and expectations. There are two main aspects of software quality:
- Quality of Design: The inherent quality built into the software's design (materials, tolerances, specifications).
- Quality of Conformance: How well the implementation adheres to the design.
Software quality assurance (SQA) is a systematic approach to building quality into the software development process. It focuses on preventing defects and improving the overall process rather than just finding and fixing defects after they occur (quality control).
The Importance of Software Quality
High software quality is paramount due to:
- Increasing Software Criticality: Software is increasingly used in safety-critical systems (e.g., aircraft control).
- Intangibility of Software: Difficult to assess quality directly; deliverables are needed for evaluation.
- Error Accumulation: Errors in early stages can cascade to later stages, making them more costly to fix.
Software Quality Assurance (SQA)
Software quality assurance is a planned and systematic set of activities designed to provide confidence that the software development process will produce high-quality software. SQA focuses on process improvement and preventing defects.
SQA Activities:
SQA activities are performed by a dedicated SQA group and involve:
- Developing an SQA plan.
- Participating in process definition.
- Reviewing development activities.
- Auditing work products.
- Managing deviations.
- Reporting non-compliance issues.
Quality Assurance vs. Quality Control
| Aspect | Quality Assurance (QA) | Quality Control (QC) |
|---|---|---|
| Focus | Process improvement; preventing defects. | Product evaluation; detecting defects. |
| Approach | Proactive; establishes processes and standards. | Reactive; identifies defects in the product. |
| Objective | Establishes and improves processes. | Identifies and corrects defects. |
| Methods | Reviews, audits, training | Testing, inspections |