Equivalence Partitioning

What Does Equivalence Partitioning Mean?

Equivalence partitioning (EP) is a method for testing software programs. In this technique, the data fed into the software to
be tested is divided into partitions of equal sizes. From each partition of data,
one test case is needed. The different test cases must test the classes of the
software continuously. This helps in the discovery of errors and bugs which may
plague the software. Each test case is defined specifically to check a specific
type of error. This speeds up the error hunting process as fewer test cases
are required.


Equivalence partitioning is also known as equivalence class partitioning (ECP).

Techopedia Explains Equivalence Partitioning

Equivalence partitioning is a testing technique based on specifications known as test cases. It is extremely
efficient, fast and easy to use, and also does not require much input data. Its
flexibility makes it suitable for testing in any stage of development of the

In this technique, the data or test cases are partitioned or divided
first to form data sets called equivalence classes or partitions. These sets
are considered as equal by the software, hence the term
“equivalence partitioning.” Because all the equivalence classes of a group are to
be considered as equal by the software, only one test case is
required from each group in order to test that specific condition for the group that
it is representing. If it works properly, then it can be concluded that others
in the group would also work properly with the software. However, if it does not
work, then the whole group can be ignored, as it can be concluded that other
cases would not work as well.


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Margaret Rouse
Technology Expert

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.