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.