Any software development organization aims to achieve high software quality. Software quality is complex and has many aspects, contrary to popular belief that software quality is just the number of bugs. The ISO/IEC 25010 standard gives eight dimensions from which to evaluate software quality. Every aspect is essential either from the customer's perspective or from the development organization's.

The Eight Dimensions of Software Quality

The following dimensions are as per the ISO/IED 25010 software quality model:

1. Functional Suitability

Functional suitability is about how well the software operates for the end-users. High-quality software will have no missing functionality, a low defect rate, and quickly solve end-user problems.

How to evaluate:

2. Performance

Performance refers to how well the software performs under various workloads. High-quality software will be scalable, have low response times, high throughput, and optimal hardware and software utilization.

How to evaluate:

  • Stress testing
  • Page load times
  • Soak testing

3. Usability

Usability refers to how easily end-users can use and benefit from the software. A highly usable software is easy to learn and use, is accessible to users with special needs, protects end-users from errors, and is pleasing to the eye.

How to evaluate:

  • User acceptance testing
  • Website engagement and conversion monitoring
  • Real user monitoring
  • Customer satisfaction survey

4. Reliability

Reliability refers to a software system's resistance and resilience to malfunctions. A reliable software works consistently over long periods, has high availability, is fault-tolerant, and recovers quickly from crashes.

How to evaluate:

  • Soak testing
  • Load testing
  • Regression testing

5. Compatibility

Compatibility refers to the software's ability to coexist and work with existing software and hardware. A highly compatible software will work seamlessly across various hardware, operating systems, and screen sizes.

How to evaluate:

  • Cross-browser testing
  • UI automation

6. Maintainability

Maintainability refers to how quickly you can modify your code to meet new requirements. High-quality code is modular, reusable, analyzable, adaptable, and easily testable. Complex code is less maintainable. However, poorly written and undocumented code is even worse.

How to evaluate:

  • Lines of Code (LOC)
  • Static code analysis
  • Cyclomatic complexity evaluation
  • Peer review

7. Portability

Portability refers to how easily you can move the software to another execution environment. High-quality portable code can adapt to evolving software and hardware platforms. It is easy to install and requires minimal external dependencies.

How to evaluate:

  • Setting realistic environments for testing.
  • Automating installation/uninstallation testing
  • Platform-specific UI and regression testing

8. Security

Security refers to the vulnerability of the software to malicious attacks and unintended end-user actions. Highly secure software is resistant to cyber-attacks. It also has a high degree of authenticity, confidentiality, non-repudiation, and accountability.

How to evaluate:

  • Vulnerability scanning
  • Malware scanning
  • Ethical hacking