Equivalence Class Testing

Introduction to Equivalence Class Testing

One of the most important technique among all other techniques used in software testing models is Equivalence Class Testing. It is regarded as the black box testing that plays an important role in the Software Testing Life Cycle. The testers who perform the testing give assurance that the results are accurate and also cover very limited amount of time in doing the input scenarios. The test cases are designed in such a way that the input data can be divided into equivalence classes and are applied to various types of testing purposes.

What is Equivalence Class Testing?

Equivalence class testing is better known as Equivalence Class Partitioning and Equivalence Partitioning. This is a renowned testing approach among all other software testing techniques in the market that allows the testing team to develop and partition the input data for analyzing and testing and based on that the software products are partitioned and divided into number of equivalence classes for testing.

• The equivalence classes that are divided perform the same operation and produce same characteristics or behavior of the inputs provided.
• The test cases are created on the basis on the different attributes of the classes and each input from the each class is used for execution of test cases, validating the software functions and moreover validating the working principles of the software products for the inputs that are given for the respective classes.
• It is also referred as the logical step in functional testing model approach that enhances the quality of test classes and by removing any redundancy or faults that can exist in the testing approach.

Types of Equivalence Class Testing

The equivalence class testing is divided into four different types that forms an integral part of testing mechanisms and perform action based on different data sets.

They are as follows:

• Weak Normal Testing Class: This type of testing uses only a single variable from each equivalence class during test cases. The word weak signifies single fault and in the testing scenario, there is only one element. The tester identifies the values in a systematic way.
• Strong Normal Testing Class: This type of testing is associated with multiple fault assumptions and test cases are required for each element from equivalence class and the testing team covers the whole equivalence class by using every possible inputs.
• Weak Robust Testing Class: This type of testing results into single fault as it is weak and the expected output from invalid test cases cannot be defined. The testers usually spend a huge amount of time for defining the expected output from the test cases. The testing team mainly focus on testing the test cases for invalid values.
• Strong Robust Testing Class: This form of class testing is redundant. So multiple fault assumptions are present and the equivalence classes are measured in the terms of valid and invalid inputs from test cases. However, for the testing team it is not feasible for reducing the redundancy.

Why do we need Equivalence Class Testing?

It is the best practice for testing purpose than Boundary value analysis that is a formation of stress and negative testing.

So we require and mainly use equivalence class testing approach for the below features:

• It uses the black box testing approach that refrain the testers to test and analyze the software product externally.
• The equivalence class testing, is also known as equivalence class portioning, which is used to subdivide or partition into multiple groups of test inputs that are of similar behavior.
• With this approach, the family is dependent on the team member, if any member works well then whole family will function well.
• This testing approach is used for other levels of testing such as unit testing, integration testing etc.
• It is well made for ECT when the input data contains discrete values and available in intervals.
• There is no such specific rule for using inputs for the test class and the tester has the option to use more than one inputs.
• If implementation is properly done, then the testing approach results into decrease in redundant test cases.
• The whole concept of equivalence class testing or partition comes from equivalence class that turns up from equivalence relations.
• It also helps in reducing the time for finding and executing the test cases while maintaining the efficiency.

Importance of Equivalence Class Testing

It is one of the powerful testing process in entire software testing approach that helps in reducing the redundancy in testing methods and making the process agile. It is one of the testing techniques that provides an indefinite amount of benefits to the testing team and ensures better quality software products to be delivered to the clients.

The list of its usefulness are as follows:

• It helps in reducing the overall number of test cases without hampering the test coverage for the applications.
• This testing approach is useful in terms of minimizing the overall execution time for test cases as it helps in minimizing the bulk data for testing purpose and at the same time maintaining its efficiency.
• The class testing is also helpful as it can be applied to all sorts of testing approaches such as unit testing, system testing, acceptance testing and integration testing that is beneficial for combining the whole testing approach into a single technique.
• The testing method also enables the testing team to focus mainly on smaller sets of data that increases the probability of finding and solving more and more defects in the software products before it get delivered to the client.
• This testing approach is also used in some cases where exhaustive testing is difficult at that moment and also maintain the overall test coverage at the same time.

Conclusion

Equivalence class testing that is purely a specification based testing is the popular and best method for testing purposes that decreases test cases required to develop a software product. This testing approach is famous worldwide for its greater test coverage and minimizing time.

This is a guide to Equivalence Class Testing. Here we discuss the introduction, types, why do we need equivalence class testing and importance. You may also have a look at the following articles to learn more –

1. Domain Testing
2. Equivalence Partitioning
3. Negative Testing
4. Black Box Testing Techniques