1. Boundary Value Analysis:

Definition: Boundary Value Analysis (BVA) is a software testing technique used to identify errors at the boundaries of input domains. It focuses on testing values at the edges of input ranges.

Example: Consider a system that accepts input values between 1 and 100. In boundary value analysis, we test the following:

• Input values just below the lower boundary (1).
• Input values at the lower boundary (1).
• Input values within the valid range (2 to 99).
• Input values at the upper boundary (100).
• Input values just above the upper boundary (101).

By testing these boundary conditions, we increase the likelihood of uncovering potential issues such as off-by-one errors or boundary-related bugs.

2. Decision Table Testing:

Definition: Decision Table Testing is a black-box testing technique used to test systems with complex business logic. It involves creating a table that lists all possible inputs and their corresponding outputs based on the rules of the system.

Example: Let's consider a banking application that determines whether a customer is eligible for a loan based on their credit score and income level. We can create a decision table like this:

Here, the decision table covers all possible combinations of credit scores and income levels, and their corresponding eligibility outcomes. Test cases are derived from this table to ensure that the system behaves correctly under various scenarios.

3. Use Case Testing:

Definition: Use Case Testing is a functional testing technique that validates the system's behavior against its specified requirements. It involves identifying and executing test cases based on the various interactions users have with the system.

Example: Let's consider an e-commerce platform. One of the primary use cases is the process of placing an order. Use case testing for this scenario would involve:

• Testing the successful placement of an order.
• Testing the placement of an order with invalid payment information.
• Testing the placement of an order with out-of-stock items.
• Testing the cancellation of an order before it's shipped.
• Testing the modification of an order after it's placed.

By testing these use cases, we ensure that the system functions correctly and meets user expectations in real-world scenarios.

4. LCSAJ Testing:

Definition: LCSAJ (Linear Code Sequence and Jump) Testing is a white-box testing technique used to ensure that every linear sequence of code is executed at least once during testing. It aims to achieve thorough coverage of code paths.

Example: Consider a function that calculates the factorial of a number. A typical implementation might use a loop to iterate through the numbers and multiply them together. LCSAJ testing for this function would involve ensuring that every line of code within the loop is executed at least once during testing.

def factorial(n):
    result = 1
    for i in range(1, n+1):
        result *= i
    return result

In this example, we would design test cases to ensure that the loop is executed with different values of 'n', covering scenarios such as positive integers, zero, and negative integers.

By employing LCSAJ testing, we aim to achieve comprehensive coverage of code execution paths, increasing confidence in the correctness of the software.

In conclusion, these testing techniques, including Boundary Value Analysis, Decision Table Testing, Use Case Testing, and LCSAJ Testing, play crucial roles in ensuring the quality and reliability of software systems by systematically identifying and addressing potential issues.