Skip to content

non-functional.md

Latest commit

 

History

History
106 lines (81 loc) · 4.83 KB

non-functional.md

File metadata and controls

106 lines (81 loc) · 4.83 KB
Raw

Non-Functional Testing

Introduction

Non-Functional Testing (NFT) is a type of software testing that focuses on how well a system performs, rather than what it does.
It evaluates performance, usability, reliability, security, and other quality attributes of an application to ensure it meets expectations beyond functional requirements.

1. Difference Between Functional and Non-Functional Testing

Aspect Functional Testing Non-Functional Testing
Focus What the system does How the system performs
Example Login functionality works correctly Login response time under load
Goal Verify feature behavior Verify quality attributes like performance, security, usability
Test Type Typically manual or automated Often automated, simulation-based, or measurement-based

2. Types of Non-Functional Testing

Type Description Example
Performance Testing Checks system speed, responsiveness, and stability under load Page load time, transaction speed
Load Testing Measures performance under expected user load 500 users accessing application simultaneously
Stress Testing Determines system limits under extreme conditions Spike testing with 2000 concurrent users
Scalability Testing Verifies if system can scale with increasing workload Adding more servers to handle more users
Reliability / Stability Testing Checks if system runs continuously without failure 24-hour uptime testing
Security Testing Ensures protection against threats and vulnerabilities Penetration testing, SQL injection check
Usability Testing Evaluates user-friendliness and experience Ease of navigation, accessibility
Compatibility Testing Ensures application works across devices, browsers, OS Chrome, Firefox, Safari, Windows, Android, iOS
Maintainability Testing Checks ease of maintenance and updates Code readability, modular design
Compliance Testing Verifies adherence to standards and regulations GDPR, HIPAA compliance

3. Key Objectives of Non-Functional Testing

  1. Ensure the application performs well under expected conditions.
  2. Verify security, stability, and reliability of the system.
  3. Validate user experience and accessibility.
  4. Ensure compliance with industry standards and regulations.
  5. Identify potential bottlenecks before production.

4. Performance Testing Example

Imagine a banking website:

  • Scenario: During salary day, thousands of users log in simultaneously.
  • Performance Test Objective: Ensure login and transaction processing time remains acceptable.
  • Result: Page load remains under 3 seconds, and the system can handle 2000 concurrent users without crashing.

5. Security Testing Example

  • Scenario: An e-commerce app handles credit card payments.
  • Objective: Ensure that sensitive user data is protected.
  • Test Cases:
    • SQL injection attempt
    • Cross-site scripting (XSS)
    • Access control validation
  • Outcome: Application should prevent unauthorized access and data breaches.

6. Tools for Non-Functional Testing

Type Tools
Performance & Load JMeter, LoadRunner, Gatling
Security OWASP ZAP, Burp Suite, Nessus
Usability Crazy Egg, Hotjar, UserTesting
Compatibility BrowserStack, Sauce Labs
Monitoring & Logging New Relic, Grafana, Prometheus

7. Best Practices

  1. Define non-functional requirements early in the project.
  2. Prioritize based on business criticality.
  3. Simulate real-world conditions during testing.
  4. Automate where possible for repeatable and measurable results.
  5. Monitor production systems for continuous validation.

8. Real-Life Scenario

For a mobile food delivery app:

  • Functional: Orders are placed correctly.
  • Non-functional:
    • App should load within 2 seconds.
    • Payment processing should handle 1000 transactions per minute.
    • App should work on Android and iOS devices.
    • Customer data must be encrypted and secure.

Summary

Non-Functional Testing ensures that the system is fast, reliable, secure, and user-friendly.
While functional testing verifies what the system does, non-functional testing ensures how well it does it under real-world conditions.

Final Takeaway

Non-Functional Testing is critical for user satisfaction, system reliability, and compliance.
A software product that meets functional requirements but fails in performance, security, or usability will fail to deliver real value to users.