CH05.L03 . BBT-2-boundary value analysis

Summary

The script discusses the Boundary Value Analysis (BVA) technique in software testing, emphasizing its importance in identifying bugs at data range boundaries. It outlines a two-step process: identifying lower and upper boundaries, then testing values just inside and outside these limits. The example provided demonstrates BVA's application with a range from 1 to 100, highlighting the need to test values like 0, 1, 2, 99, 100, and 101. The script also mentions combining BVA with Equivalence Partitioning to optimize test cases, reducing them to five from six by eliminating redundant tests. It concludes by noting BVA's applicability to numbers and dates, and the selection of test values for decimal boundaries.

Takeaways

• 🔍 Bugs often occur at the boundaries of data ranges, specifically at the first and last numbers.
• 📝 The requirement specifies a data range from 1 to 100, inclusive, meaning both 1 and 100 are valid inputs.
• 🛠 Developers might overlook inclusive boundaries in code, leading to incorrect implementations without the use of >= or <=.
• 📚 Black box testing is used when the internal code is not visible, necessitating the use of testing techniques like Boundary Value Analysis (BVA).
• 📝 BVA involves two steps: identifying the lower and upper boundaries and then testing values just above and below these boundaries.
• 📋 The BVA technique suggests creating test cases for the exact boundary values, one value less than the lower boundary, one value more than the lower boundary, one value less than the upper boundary, and one value more than the upper boundary.
• 🔢 The script provides an example using the range 1 to 100, suggesting test cases for 0, 1, 2, 99, 100, and 101.
• 💡 By combining BVA with Equivalence Partitioning (EP), it's possible to reduce the number of test cases by considering some values as part of the same partition.
• 👉 The script concludes that with BVA and EP, only 5 test cases are needed to cover the range 1 to 100 effectively.
• 📉 BVA is particularly applicable to numeric and date values, which have clear boundaries.
• 📌 When boundaries are decimal numbers, test values should be chosen just above and below the boundary, such as 10.1 and 9.9.
• 🔑 The script emphasizes that BVA, when used in conjunction with EP, covers all boundary issues that may arise with numeric and date inputs.

Q & A

What is the primary focus of bugs in software with a range of data?

The primary focus of bugs in software with a range of data is at the boundaries, specifically the first and last numbers of the range.

What does it mean when a range is inclusive?

An inclusive range means that both the lower and upper boundaries, such as 1 and 100 in the example, are included in the data set.

Why might developers forget to include the boundaries in their code?

Developers might forget to include the boundaries in their code by not using the correct signs (>= or <=), which can lead to the exclusion of the boundary values like 1 and 100.

What is the Boundary Value Analysis (BVA) technique?

The Boundary Value Analysis (BVA) technique is a testing method that focuses on the boundaries of input values to ensure that all potential issues are covered.

What are the two steps involved in the BVA technique?

The two steps in the BVA technique are: 1) Identifying the boundaries (lower and upper), and 2) Testing values just above and below each boundary.

What are the specific test cases suggested for the example range of 1 to 100?

The specific test cases for the range of 1 to 100 include values at the lower boundary (1), upper boundary (100), below the lower boundary (0), above the lower boundary (2), below the upper boundary (99), and above the upper boundary (101).

How can the number of test cases be reduced by combining BVA and Equivalence Partitioning (EP)?

By combining BVA and EP, you can consider the two middle numbers (2 and 99) as part of the same partition, reducing the number of test cases needed to 5 instead of 6.

What is the significance of identifying valid and invalid values in testing?

Identifying valid and invalid values helps in designing test cases that cover all possible scenarios and ensures that the software behaves correctly under both expected and unexpected conditions.

Why is BVA particularly applicable to numbers and dates?

BVA is particularly applicable to numbers and dates because these types of data inherently have boundaries that can be tested for potential issues.

How should test values be chosen when dealing with decimal boundaries?

When dealing with decimal boundaries, such as 10.0, test values should be chosen just above (e.g., 10.1) and just below (e.g., 9.9) the boundary to ensure thorough testing.

What is the main advantage of using BVA in conjunction with Equivalence Partitioning?

The main advantage of using BVA in conjunction with Equivalence Partitioning is that it covers all the boundaries where most problems may occur with numeric and date data inputs, making the testing process more comprehensive.