Boundary Value Analysis in Testing

Boundary value analysis (BVA) is a software testing technique to identify and test a system’s input and output boundaries. It is beneficial for finding errors or defects at the edges or boundaries of input ranges.
The basic idea behind BVA is that if a system is likely to fail, it is more likely to do so at the boundaries of the input domain rather than in the middle of the range.

Here’s how boundary value analysis works:

1. Identify the input variables: Identify the input variables or parameters the software or system will accept. These could be numerical values, text inputs, or other data types.
2. Determine the boundary values: For each input variable, determine the boundary values. These are the minimum and maximum values allowed for that input.
3. Create test cases: Generate test cases for the following categories for each input variable:
  • On the boundary: Test with values just on the edge of the valid range.
  • Just inside the boundary: Test with values immediately inside the valid range.
  • Just outside the boundary: Test with values immediately outside the valid range.
  • Far outside the boundary: Test with values significantly outside the valid range.
  1. Execute the test cases: Execute the test cases and observe the system’s behavior. Check for any unexpected errors or issues that occur at the boundaries.
  2. Analyze the results: Analyze the test results to identify and document any defects or anomalies at the boundary values.
Boundary value analysis is practical because it focuses on the areas where mistakes are most likely to occur due to coding errors, such as off-by-one errors, truncation, rounding, or other boundary-related issues. It helps in the early detection of software defects and improves the overall quality of the software.