Performance Testing
Performance Testing is the process of evaluating how a software application behaves in terms of speed, responsiveness, and stability under expected and peak usage conditions.
Performance testing answers: “Is the application fast and stable for users?”
1. Definition
Performance Testing is the process of evaluating how a software application behaves in terms of speed, responsiveness, and stability under expected and peak usage conditions.
Performance testing answers: “Is the application fast and stable for users?”
2. Purpose of Performance Testing
- Ensure acceptable response times
- Identify performance bottlenecks
- Validate system stability
- Prevent user dissatisfaction due to slowness
3. Manual Tester’s Scope (Conceptual)
Manual testers focus on:
- Observing response times
- Identifying slow pages or actions
- Detecting timeouts and delays
- Reporting performance concerns
(Load and stress testing are typically done using tools, but awareness is essential.)
4. Types of Performance Testing (High-Level)
4.1 Load Testing
- System behavior under expected user load
4.2 Stress Testing
- System behavior beyond capacity
4.3 Spike Testing
- Sudden load increase handling
4.4 Endurance Testing
- Stability over long durations
5. Key Performance Indicators (Conceptual)
- Response time
- Throughput
- Latency
- Error rate
6. Performance Testing vs Functional Testing
| Aspect | Performance Testing | Functional Testing |
|---|---|---|
| Focus | Speed & stability | Correctness |
| User impact | High | Medium |
| Measurement | Time-based | Pass/Fail |
7. Real-Time Example
User clicks “Submit”:
- Acceptable response: ≤ 3 seconds
- Delay beyond threshold → performance issue
8. Entry & Exit Criteria
Entry Criteria
- Stable build available
- Key user flows identified
Exit Criteria
- Major performance risks identified
- Performance expectations met or documented
9. Common Performance Issues (Manual Observation)
- Slow page loads
- Long wait times after actions
- Application freezes
- Timeout errors
10. Common Mistakes
- Ignoring performance until production
- Assuming functional correctness equals good performance
- Not reporting perceived slowness
11. Interview-Ready Answers
Short answer:
Performance testing evaluates the speed, responsiveness, and stability of an application under various conditions.
Detailed answer:
Performance testing ensures that an application responds quickly and remains stable for users under expected and peak workloads.
12. Key Takeaway
Performance Testing ensures the application is usable and responsive, not just functionally correct.