Software Testing Lifecycle Guide - STLC & Best Practices

📋 Software Testing Life Cycle (STLC) Phases

Requirement Analysis

↓

Test Planning

↓

Test Case Development

↓

Test Environment Setup

↓

Test Execution

↓

Test Cycle Closure

Phase 1: Requirement Analysis

Objective: Understand what needs to be tested

Activities:

Review functional & non-functional requirements
Identify testable requirements
Determine test priorities
Identify testing types required
Prepare Requirement Traceability Matrix (RTM)

Deliverables: RTM, Automation feasibility report

Phase 2: Test Planning

Objective: Define testing approach and resources

Activities:

Estimate testing effort
Select testing tools
Define test strategy
Allocate resources
Identify entry/exit criteria
Risk assessment

Deliverables: Test Plan, Test Strategy Document, Effort Estimation

Phase 3: Test Case Development

Objective: Create test cases and test data

Activities:

Write detailed test cases
Create test scripts (for automation)
Prepare test data
Review & baseline test cases
Update RTM

Deliverables: Test Cases, Test Scripts, Test Data

Phase 4: Test Environment Setup

Objective: Prepare testing environment

Activities:

Setup test environment (hardware/software)
Configure test data
Perform smoke testing
Verify environment readiness

Deliverables: Environment ready, Smoke test results

Phase 5: Test Execution

Objective: Execute tests and log defects

Activities:

Execute test cases
Document test results
Log defects
Retest fixed defects
Regression testing
Update test status

Deliverables: Test execution reports, Defect reports, RTM updates

Phase 6: Test Cycle Closure

Objective: Complete testing and document learnings

Activities:

Verify all defects closed/deferred
Prepare test summary report
Collect metrics
Conduct retrospectives
Archive test artifacts

Deliverables: Test closure report, Lessons learned, Test metrics

🎯 Test Strategies

1. Proactive Strategy

Testing starts early in SDLC, before code is written. Focuses on preventing defects.

Risk-Based Testing: Prioritize testing based on risk assessment
Requirements-Based Testing: Test cases derived from requirements
Early Test Design: Test cases created during requirements phase

2. Reactive Strategy

Testing begins after code is developed. Focuses on finding defects.

Exploratory Testing: Simultaneous learning, test design & execution
Session-Based Testing: Time-boxed exploratory sessions
Error Guessing: Based on tester's experience

3. Methodical Strategy

Systematic approach using established test techniques and standards.

Checklist-Based: Predefined checklists
Standards-Based: Following industry standards (ISO, IEEE)
Quality Characteristics-Based: Testing based on quality models

4. Analytical Strategy

Use analysis to determine testing focus areas.

Risk Analysis: Focus on high-risk areas
Coverage Analysis: Ensure adequate code/requirement coverage
Cause-Effect Analysis: Identify causes of defects

5. Model-Based Strategy

Tests derived from models of system behavior.

State Transition Testing: Based on state diagrams
Use Case Testing: Based on use case models
Decision Table Testing: Based on business rules

🔍 Test Types

Type	Purpose	When to Use	Tools
Functional Testing	Verify features work as expected	Every release	Selenium, Playwright, TestNG
Non-Functional Testing	Test performance, security, usability	Before major releases	JMeter, LoadRunner, OWASP ZAP
Regression Testing	Ensure new changes don't break existing features	After every code change	Selenium, CI/CD pipelines
Smoke Testing	Verify critical functionalities work	After build deployment	Quick automated scripts
Sanity Testing	Quick check on specific functionality	After minor fixes	Manual or automated
Integration Testing	Test interaction between components	After unit testing	JUnit, TestNG, REST Assured
System Testing	End-to-end testing of complete system	Before UAT	Selenium, Playwright
Acceptance Testing	Verify system meets business requirements	Before production	Cucumber, Selenium
Performance Testing	Check speed, scalability, stability	Load testing phase	JMeter, Gatling, K6
Security Testing	Identify vulnerabilities	Security audit phase	OWASP ZAP, Burp Suite
Usability Testing	Evaluate user-friendliness	UX review phase	Manual testing, User feedback
Compatibility Testing	Check across browsers/devices/OS	Cross-platform releases	BrowserStack, Sauce Labs

Detailed Test Types

Functional Testing

Unit Testing: Individual components
Integration Testing: Component interactions
System Testing: Complete system
UAT: Business perspective validation

Non-Functional Testing

Performance: Load, Stress, Spike, Endurance testing
Security: Vulnerability, Penetration, Risk assessment
Usability: User experience evaluation
Compatibility: Browser, OS, Device compatibility
Reliability: System uptime and recovery
Scalability: Handling increased load

📊 Test Levels

┌─────────────────────────┐

│ Acceptance Testing │ ← Business Users

├─────────────────────────┤

│ System Testing │ ← QA Team

├─────────────────────────┤

│ Integration Testing │ ← Dev + QA

├─────────────────────────┤

│ Unit Testing │ ← Developers

└─────────────────────────┘

Level 1: Unit Testing

Aspect	Details
Focus	Individual units/components
Who	Developers
When	During development
Tools	JUnit, TestNG, Mockito
Coverage	Classes, methods, functions

Level 2: Integration Testing

Aspect	Details
Focus	Component interactions, APIs, data flow
Who	Developers + QA
When	After unit testing
Tools	REST Assured, Postman, SoapUI
Approaches	Big Bang, Top-Down, Bottom-Up, Sandwich

Level 3: System Testing

Aspect	Details
Focus	Complete integrated system
Who	QA Team
When	After integration testing
Tools	Selenium, Playwright, Cypress
Coverage	Functional & non-functional requirements

Level 4: Acceptance Testing

Aspect	Details
Focus	Business requirements validation
Who	Business users, Stakeholders
When	Before production release
Types	UAT, Alpha, Beta, Contract testing
Tools	Cucumber, SpecFlow, FitNesse

🛠️ Test Design Techniques

Black Box Testing Techniques

1. Equivalence Partitioning

Divide input data into partitions of equivalent data where each partition is tested once.

            Example: Age field (1-150) Valid Partition: 1-150
            Invalid Partitions: <1, >150 Test Cases: - Age = 25 (valid) - Age =
            0 (invalid) - Age = 151 (invalid)
          

2. Boundary Value Analysis

Test values at boundaries between partitions.

            Example: Age field (18-60) Boundary Values: 17, 18,
            60, 61 Test Cases: - Age = 17 (just below min) - Age = 18 (min
            boundary) - Age = 60 (max boundary) - Age = 61 (just above max)
          

3. Decision Table Testing

Test combinations of inputs and their corresponding outputs.

Condition	Rule 1	Rule 2	Rule 3	Rule 4
Valid Username	Y	Y	N	N
Valid Password	Y	N	Y	N
Action	Login	Error	Error	Error

4. State Transition Testing

Test system behavior through different states.

            Example: ATM PIN Entry States: Locked, Attempt 1,
            Attempt 2, Unlocked Transitions: - Locked → Correct PIN → Unlocked -
            Attempt 1 → Wrong PIN → Attempt 2 - Attempt 2 → Wrong PIN → Locked
          

5. Use Case Testing

Derive test cases from use cases/user stories.

White Box Testing Techniques

1. Statement Coverage

Ensure every statement in code is executed at least once.

2. Branch Coverage

Ensure every branch (if/else, switch cases) is executed.

3. Path Coverage

Execute all possible paths through the code.

4. Condition Coverage

Test all boolean sub-expressions separately.

🤖 Test Automation Strategy

Test Automation Pyramid

┌───────────────┐

│ UI Tests │ ← 10% (Manual + Automated)

├───────────────┤

┌─┴───────────────┴─┐

│ Integration Tests │ ← 30% (Automated)

├───────────────────┤

┌─┴───────────────────┴─┐

│ Unit Tests │ ← 60% (Automated)

└───────────────────────┘

When to Automate

✅ AUTOMATE:

Regression test suites
Smoke/Sanity tests
Repetitive tests
Data-driven tests
Performance/Load tests
API tests
Critical path scenarios

❌ DON'T AUTOMATE:

One-time tests
Unstable features
Complex visual validation
Usability testing
Exploratory testing
Tests requiring frequent updates

Automation Framework Types

Framework	Description	Pros	Cons
Linear	Record and playback	Easy to create	Not maintainable
Modular	Divide application into modules	Reusable modules	Requires planning
Data-Driven	Separate test data from scripts	Easy data variation	Data dependency
Keyword-Driven	Keywords represent actions	Non-technical friendly	Initial effort high
Hybrid	Combination of above	Flexible, powerful	Complex setup
BDD	Behavior-driven (Cucumber)	Business readable	Learning curve

CI/CD Integration

            Pipeline Stages:

            1. Code Commit → Trigger build 2. Build → Compile code 3. Unit Tests
            → Run unit tests 4. Deploy to Test Environment 5. Integration Tests
            → API tests 6. UI Tests → Selenium/Playwright tests 7. Performance
            Tests → Load tests 8. Security Scans → Vulnerability check 9. Deploy
            to Staging 10. Smoke Tests → Critical path 11. Manual Testing (if
            needed) 12. Deploy to Production
          

Test Automation Tools Comparison

Tool	Type	Language	Best For
Selenium	UI	Java, Python, C#, JS	Cross-browser testing
Playwright	UI	Java, Python, JS, C#	Modern web apps, auto-wait
Cypress	UI	JavaScript	Frontend developers
REST Assured	API	Java	REST API testing
Postman	API	JavaScript	API manual + automation
JMeter	Performance	Java	Load/Stress testing
Cucumber	BDD	Java, Ruby, JS	Behavior-driven testing

✨ Testing Best Practices

Test Case Design

Write clear, concise test cases
One test case = one objective
Include prerequisites and test data
Make test cases independent
Use descriptive names
Maintain traceability to requirements
Review test cases before execution

Defect Management

Report defects immediately
Include steps to reproduce
Attach screenshots/logs
Assign severity and priority
Verify fixes before closing
Track defect metrics

Test Data Management

Separate test data from test scripts
Use realistic data
Protect sensitive data (masking)
Version control test data
Create data setup/teardown scripts
Use data generation tools

Test Environment

Mirror production as closely as possible
Maintain separate environments (Dev, QA, Staging, Prod)
Document environment configuration
Implement access controls
Regular environment refreshes
Monitor environment health

Test Metrics to Track

Metric	Formula	Purpose
Test Coverage	(Tested / Total) × 100	Measure completeness
Defect Density	Defects / Size (KLOC)	Code quality indicator
Defect Removal Efficiency	(Defects Found / Total Defects) × 100	Testing effectiveness
Test Execution Rate	Tests Executed / Time	Team productivity
Pass Rate	(Passed / Executed) × 100	Build stability
Automation ROI	(Manual Cost - Automation Cost) / Automation Cost	Automation value

Shift-Left Testing

Early Testing Approach:

Test planning during requirements phase
Static testing (reviews, inspections)
Unit testing by developers
TDD (Test-Driven Development)
BDD (Behavior-Driven Development)
Early defect detection → Lower costs

Shift-Right Testing

Production Testing:

Monitoring and logging
A/B testing
Canary releases
Feature flags
Real user monitoring (RUM)
Chaos engineering

📋 Software Testing Life Cycle (STLC) Phases

Phase 1: Requirement Analysis

Phase 2: Test Planning

Phase 3: Test Case Development

Phase 4: Test Environment Setup

Phase 5: Test Execution

Phase 6: Test Cycle Closure

🎯 Test Strategies

1. Proactive Strategy

2. Reactive Strategy

3. Methodical Strategy

4. Analytical Strategy

5. Model-Based Strategy

🔍 Test Types

Detailed Test Types

Functional Testing

Non-Functional Testing

📊 Test Levels

Level 1: Unit Testing

Level 2: Integration Testing

Level 3: System Testing

Level 4: Acceptance Testing

🛠️ Test Design Techniques

Black Box Testing Techniques

1. Equivalence Partitioning

2. Boundary Value Analysis

3. Decision Table Testing

4. State Transition Testing

5. Use Case Testing

White Box Testing Techniques

1. Statement Coverage

2. Branch Coverage

3. Path Coverage

4. Condition Coverage

🤖 Test Automation Strategy

Test Automation Pyramid

When to Automate

Automation Framework Types

CI/CD Integration

Test Automation Tools Comparison

✨ Testing Best Practices

Test Case Design

Defect Management

Test Data Management

Test Environment

Test Metrics to Track

Shift-Left Testing

Shift-Right Testing

📚 Related Guides & Cheatsheets

🌐 REST API Testing

�� OOP in Java

🔍 Selenium Cheatsheet

🎭 Playwright Cheatsheet