Test case design techniques

Software Testing Lifecycle

What is Test Case Design?

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• Test Case Design involves creating test cases to verify the functionality and quality of a software product.

• Ensures comprehensive and effective testing.

• Utilizes various techniques to enhance coverage and accuracy.

Why is it Important?

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• Maximum Coverage: Ensures all possible usage scenarios are tested.

• Efficiency: Reduces redundancy and optimizes resources.

• Defect Detection: Identifies errors early before release.

Main Categories of Techniques

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• Black-box Testing (Functional/Behavioral)

• White-box Testing (Structural/Code-based)

• Experience-based Testing (Exploratory/Intuitive)

Black-box Techniques

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• Equivalence Partitioning (EP): Divides input data into valid and invalid partitions.

• Boundary Value Analysis (BVA): Tests values at and near input boundaries.

• Decision Table Testing: Uses tables mapping input combinations to outputs based on rules.

• State Transition Testing: Tests systems with defined states and transitions.

• Use Case Testing: Tests complete business scenarios from the end-user's perspective.

White-box Techniques

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• Statement Coverage: Ensures all code statements are executed at least once.

• Branch Coverage: Verifies all branches from decision points are tested.

• Path Coverage: Tests all possible paths through the code.

• Condition Coverage: Evaluates each Boolean condition for both TRUE and FALSE outcomes.

• Multiple Condition Testing: Tests all combinations of multiple conditions.

Experience-based Techniques

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• Exploratory Testing: Simultaneous learning, test design, and execution.

• Error Guessing: Relies on the tester's intuition and experience to predict problem areas.

Example of Applying Techniques

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• EP & BVA: Testing input fields like age (e.g., 18–60).

• State Transition: Verifying transitions in order statuses (e.g., "Processing" → "Shipped").

• Decision Table: Testing combinations of conditions for discount eligibility.

Advantages of Applying Techniques

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• Improved Software Quality: Comprehensive testing leads to higher quality.

• Reduced Risk of Missed Defects: Thorough coverage minimizes undetected issues.

• Optimized Testing Process: Efficient use of resources and time.

• Enhanced Tester Effectiveness: Structured approach aids testers in identifying defects.

When to Apply Each Technique

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• EP & BVA: For input validation and boundary conditions.

• State Transition & Decision Table: For complex logic and business processes.

• Exploratory & Error Guessing: For identifying unexpected defects.

Best Practices in Test Case Design

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• Use standard templates for consistency.

• Ensure traceability to requirements.

• Regularly update test cases to reflect changes in the product.

• Conduct reviews to identify gaps or improvements.

Conclusion

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• Test case design techniques are fundamental for effective and efficient software testing.

• Their proper application ensures high-quality products and satisfied end-users.