Boundary value analysis & equivalence Partitioning with Example

Equivalence Partitioning:

In this method the input domain data is divided into different equivalence data classes

Boundary value analysis:

‘Boundary value analysis’ testing technique is used to identify errors at boundaries rather than finding those exist in center of input domain

E.g.: If you are testing for an input box accepting numbers from 1 to 1000 then- 

Test cases for input box accepting numbers between 1 and 1000 using Equivalence Partitioning:
1) One input data class with all valid inputs. Pick a single value from range 1 to 1000 as a valid test case. If you select other values between 1 and 1000 then result is going to be same. So one test case for valid input data should be sufficient.

2) Input data class with all values below lower limit. I.e. any value below 1, as a invalid input data test case.

3) Input data with any value greater than 1000 to represent third invalid input class.

Test cases for input box accepting numbers between 1 and 1000 using Boundary value analysis:

1) Test cases with test data exactly as the input boundaries of input domain i.e. values 1 and 1000 in our case.

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2) Test data with values just below the extreme edges of input domains i.e. values 0 and 999.

3) Test data with values just above the extreme edges of input domain i.e. values 2 and 1001.