Boundary value analysis (BVA) and equivalence partitioning (EP) are both software testing techniques used to design test cases effectively while reducing redundancy and maximizing test coverage.

Equivalence Partitioning (EP):

– EP divides the input domain of a system into partitions or classes of equivalent data.

– Test cases are then designed using representative values from each partition, aiming to ensure that all classes of input are tested.

– It’s based on the assumption that if one value in an equivalence class passes a test, all values in that class should also pass.

– For example, suppose a system accepts input values from 1 to 100. EP might divide this range into three partitions: 1-33, 34-67, and 68-100. Test cases would then be designed using one value from each partition to ensure coverage across the entire range.

Boundary Value Analysis (BVA):

– BVA focuses on testing the boundaries of equivalence classes, as errors often occur at the boundaries rather than within the ranges.

– Test cases are designed using the minimum, maximum, and just beyond the minimum and maximum values of each partition.

– This technique helps uncover errors that may not be detected by testing within the equivalence classes alone.

– Building on the previous example, for the partition 1-33, BVA would include test cases for values like 1, 33, 0, and 34.

Example:

Consider a simple login system where usernames must be between 5 and 15 characters, and passwords must be at least 8 characters long. Using EP and BVA:

1. Equivalence Partitioning:

– Username partition: Less than 5 characters, 5-15 characters, more than 15 characters.

– Password partition: Less than 8 characters, 8 or more characters.

– Test cases:

– Username: “abc”, “abcdefghijk”, “abcdefghijklmnopq”

– Password: “1234567”, “12345678”

2. Boundary Value Analysis:

– Username: “abc”, “abcde”, “abcdef”, “abcdefghijk”, “abcdefghijklmnopq”

– Password: “1234567”, “12345678”, “123456789”, “1234567890”

Using these techniques, you can design a set of test cases that effectively cover the input space while minimizing redundancy.