Software Test Automation And Quality Metrics
Software Test Automation
Software Test Automation is the process of using tools and scripts to automatically execute test cases, compare actual results with expected results, and generate test reports with minimal human intervention.
Why Automation is Needed
- Manual testing is time‑consuming
- Repetitive test cases need frequent execution
- Faster software releases (Agile & DevOps)
Real‑life example: Instead of manually checking attendance every day, a biometric system automatically records attendance.
Skills Needed for Automation Testing
Automation testing requires a combination of technical and analytical skills.
Key Skills
| Skill | Explanation |
|---|---|
| Programming Knowledge | Languages like Java, Python, JavaScript |
| Testing Concepts | Understanding SDLC, STLC, test cases |
| Automation Tools | Selenium, UFT, TestNG |
| Analytical Skills | Identifying what to automate |
| Debugging Skills | Finding script errors |
| Communication | Reporting defects clearly |
Example: An automation tester writes Selenium scripts to test a login page.
Scope of Automation Testing
Not all test cases are suitable for automation.
Suitable for Automation
- Regression testing
- Smoke testing
- Load and performance testing
- Data‑driven testing
Not Suitable for Automation
- Usability testing
- One‑time test cases
- Exploratory testing
Example: Login functionality tested daily → automate UI color change test → manual
Design and Architecture for Automation
Automation architecture defines how automation components are organized.
Common Automation Frameworks:
- Linear Framework – Simple scripts
- Data‑Driven Framework – Test data separated
- Keyword‑Driven Framework – Keywords control actions
- Hybrid Framework – Combination of multiple frameworks
Architecture Components
- Test scripts
- Test data
- Object repository
- Reporting module
Example: Hybrid framework used in enterprise applications.
Requirements for a Test Automation Tool
A good automation tool must meet certain requirements.
| Requirement | Description |
| Ease of Use | Simple scripting |
| Language Support | Java, Python, etc. |
| Reporting | Clear reports |
| Integration | CI/CD tools |
| Reusability | Reusable scripts |
Example: Selenium integrates with Jenkins for continuous testing.
Challenges in Automation Testing
Automation testing has several challenges.
Major Challenges
- High initial cost
- Tool selection difficulty
- Script maintenance
- Dynamic UI changes
- Skilled resource requirement
Example: Minor UI changes can break automation scripts.
Tracking the Bug
Bug tracking is the process of recording, monitoring, and managing defects.
Bug Life Cycle
- New
- Assigned
- Open
- Fixed
- Retest
- Closed
Bug Tracking Tools
- JIRA
- Bugzilla
- Mantis
Example: A login bug reported in JIRA and assigned to developer.
Debugging in Automation Testing
Debugging is the process of identifying and fixing errors in automation scripts.
Common Debugging Issues
- Incorrect locators
- Synchronization problems
- Environment issues
Debugging Techniques
- Breakpoints
- Logs
- Step‑by‑step execution
Example: Fixing a broken XPath locator in Selenium.
Summary Table
| Topic | Key Point |
| Automation | Saves time & effort |
| Skills | Programming + Testing |
| Scope | Repetitive testing |
| Architecture | Framework based |
| Challenges | Maintenance cost |
| Bug Tracking | Manage defects |
| Debugging | Fix script errors |
Testing Software System Security
Software system security testing ensures that data, functionality, and system resources are protected from unauthorized access, attacks, or damage.
Objectives of Security Testing
- Protect confidential data
- Prevent unauthorized access
- Ensure data integrity
- Maintain system availability
Types of Security Testing
| Type | Purpose | Example |
|---|---|---|
| Vulnerability Testing | Identify weaknesses | Finding open ports |
| Penetration Testing | Simulate attacks | Ethical hacking |
| Authentication Testing | Verify user identity | Login/password test |
| Authorization Testing | Access control | Admin vs user rights |
Real-life example: Security check at airport ensures only authorized people enter restricted areas.
Six Sigma
Six Sigma is a quality improvement methodology focused on reducing defects and variations in processes.
Key Goal: Achieve near-perfect quality (3.4 defects per million opportunities).
DMAIC Model
| Phase | Meaning |
| Define | Identify problem |
| Measure | Collect data |
| Analyze | Find root cause |
| Improve | Implement solution |
| Control | Maintain improvement |
Example: Reducing bugs in a banking application release cycle.
Total Quality Management (TQM)
TQM is a management approach where quality is responsibility of everyone.
Principles of TQM
- Customer focus
- Continuous improvement
- Employee involvement
- Process approach
Real-life example: Every employee in a hotel ensures customer satisfaction.
Complexity Metrics and Models
Complexity metrics measure how complex software code is, which affects quality and maintainability.
Common Metrics
| Metric | Description |
| Cyclomatic Complexity | Number of independent paths |
| Lines of Code (LOC) | Size of program |
| Halstead Metrics | Operators & operands |
Example: Higher complexity → more bugs → harder testing.
Quality Management Metrics
These metrics measure software quality performance.
Examples
| Metric | Purpose |
| Defect Density | Defects per size |
| Test Coverage | % code tested |
| Mean Time to Failure | Reliability |
Availability Metrics
Availability measures system uptime.
- Formula: Availability = Uptime / (Uptime + Downtime)
- Example: 99.9% availability means very little downtime.
- Real-life example: ATM machine availability.
Defect Removal Effectiveness (DRE)
DRE measures how effectively defects are removed before release.
- Formula: DRE = Defects removed before release / Total defects
- Importance: Higher DRE = better quality.
Failure Mode and Effects Analysis (FMEA)
FMEA identifies possible failures and their impact.
Key Elements
- Failure mode
- Effect
- Cause
- Risk Priority Number (RPN)
Example: Failure of payment gateway → transaction loss.
Quality Function Deployment (QFD)
- QFD converts customer requirements into technical specifications.
- Tool Used: House of Quality matrix.
- Example: Customer wants fast app → optimize response time.
Taguchi Quality Loss Function
- Taguchi states that any deviation from target quality causes loss, even within limits.
- Formula: Loss = k(x − target)²
- Example: Slight delay in app response reduces customer satisfaction.
Cost of Quality (COQ)
Cost of quality includes costs incurred to ensure quality and costs due to failures.
Types of COQ
| Cost Type | Description |
| Prevention Cost | Avoid defects |
| Appraisal Cost | Testing & inspection |
| Internal Failure | Fix before release |
| External Failure | Fix after release |
Example: Bug found after release costs more than before release.
Summary Table
| Topic | Focus |
| Security Testing | Protect system |
| Six Sigma | Reduce defects |
| TQM | Continuous quality |
| Complexity Metrics | Code difficulty |
| Availability | System uptime |
| DRE | Defect removal |
| FMEA | Risk analysis |
| QFD | Customer needs |
| COQ | Quality cost |