Software Quality Assurance (SQA) & ISO 9000 Quality Standards

Software Quality Assurance (SQA)

SQA is a planned and systematic set of activities required to provide adequate confidence that the software product conforms to its requirements and quality expectations. It is a process-oriented, prevention-focused discipline — not just testing.

Key SQA elements (activities):

1. Quality standards and procedures — define how development is done (standards: project plan conformance, SRS standards, design/coding standards, testing standards).
2. Process & product reviews — formal technical reviews (design reviews, code walkthroughs/inspections) to find defects early.
3. Software testing — verification & validation at all levels (unit, integration, system, acceptance).
4. Configuration management — control of changes and versions (SCM audit).
5. Measurement & metrics — collecting defect, effort, and coverage data for quality control.
6. Documentation & record keeping — evidence that the process was followed.
7. Audits and management control — independent SQA audits ensure the planned process is actually performed (SQA plan, SQA audit, reporting).

SQA vs Testing: SQA focuses on improving the process to prevent defects; testing focuses on finding defects in the product. SQA encompasses reviews, audits, standards, and the overall quality infrastructure — testing is one part.

ISO 9000 Quality Standards

ISO 9000 is a family of international standards for Quality Management Systems (QMS) published by the International Organization for Standardization (ISO). It is generic (applies to any organization/product, including software) — it certifies that a company has a documented, consistent quality system, not that a specific product is perfect.

Core documents:

• ISO 9000 — fundamentals and vocabulary of quality management systems.
• ISO 9001 — requirements (the certifiable standard): a QMS based on process approach, customer focus, planning, resource management, product realization, measurement/analysis, and continual improvement.
• ISO 9004 — guidance for performance improvement.

Key principles of ISO 9000/9001:

1. Customer focus
2. Leadership
3. Engagement of people
4. Process approach
5. Improvement (continuous)
6. Evidence-based decision making
7. Relationship management

For software: ISO 9000-3 provides guidelines for applying ISO 9001 to software development, maintenance, and support. Certification requires documented processes (quality manual, procedures, work instructions) and audits demonstrating conformance.

ISO 9000 vs Capability Maturity Models

Aspect	ISO 9000/9001	SEI CMM/CMMI
Nature	Generic quality management standard (any industry)	Software-specific process maturity model
Goal	Certify that a documented QMS exists & is followed	Assess process maturity level (1–5) and guide improvement
Focus	Compliance with the quality system	Continuous process improvement capability
Software-specific	ISO 9000-3 for software	Yes, designed for software

Summary table

Element	Description
SQA	Systematic, planned activities to ensure the process/product conform to requirements — reviews, audits, standards, metrics, config management
ISO 9000	International QMS standard family; ISO 9001 gives requirements; certifies a documented, effective quality system
ISO 9000-3	Software-specific guideline for applying ISO 9001

Summary: SQA ensures software is built by a disciplined, auditable process that prevents defects (reviews, audits, standards, metrics, SCM); ISO 9000/9001 provides an internationally recognized quality-management framework, with ISO 9000-3 adapting it to software — both emphasize process quality as the foundation of product quality.