Equivalence Partitioning

Definition of Equivalence Partitioning

Equivalence Partitioning is a software testing technique used to minimize the number of test cases while maximizing test coverage. It involves dividing input data into mutually exclusive groups or partitions, where all the data in each partition is considered equivalent in terms of functionality. Test cases are created for each partition, ensuring that the system is tested across a representative sample of input values without redundancy.


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Key Takeaways

  1. Equivalence Partitioning is a testing technique that divides the input data of a software application into equivalent partitions, where each partition contains inputs that produce similar results.
  2. By selecting one test case from each partition, testers can efficiently test the application since the inputs in each partition are expected to behave in the same way. This helps to reduce the number of test cases while maintaining the effectiveness of the testing process.
  3. Equivalence Partitioning is widely used in both functional and non-functional testing, helping testers to identify errors, improve the software’s performance, and minimize the time spent on repetitive testing tasks.

Importance of Equivalence Partitioning

Equivalence Partitioning is an important technology term because it is a widely used black-box testing technique that helps improve the efficiency and effectiveness of software testing.

It allows testers to identify and categorize input data into groups, or partitions, that are expected to exhibit similar behavior and produce the same output, given the software under test.

By selecting input test cases from each partition, it helps ensure extensive test coverage while reducing the number of redundant test cases.

This approach saves both time and resources in the testing process while simultaneously increasing the probability of detecting defects, ultimately contributing to the overall quality and robustness of the software.


Equivalence Partitioning is a widely adopted black-box testing technique aiming to streamline the testing process and enhance its efficiency. The fundamental purpose of this method is to classify a large set of test input data into smaller, equivalent partitions, or classes, which share similar attributes and are expected to yield comparable outcomes when used as input for the software under test.

By doing so, we significantly reduce the number of test cases and resources needed by identifying the representative values within each partition, which in turn, enables testers to uncover potential bugs and edge cases in an optimal manner. In software testing, Equivalence Partitioning aids in covering a wide range of test scenarios while minimizing redundancy and effort.

Testers ascertain that each partition is functionally equivalent, meaning that testing even a single input value within it should provide sufficient insight into the entire partition’s functioning. This approach allows testers to streamline the process and distinguish between valid and invalid input data, leading to a comprehensive analysis of the system’s functionality.

Moreover, it assists in detecting discrepancies, defects, and issues in the initial stages of software development, improving both the software’s quality and reliability and reducing the time required for extensive testing.

Examples of Equivalence Partitioning

Equivalence Partitioning is a software testing technique used to reduce the number of test cases required to ensure comprehensive test coverage. It involves dividing the input data into equivalent classes, such that testing one value from each class is sufficient to cover the entire input range. Here are three real-world examples of how Equivalence Partitioning has been used:

Online Form Validation: In an online registration system where users need to enter their age, the input range can be divided into different partitions such as “under 18,” “18 to 65,” and “over

” Applying the Equivalence Partitioning technique can help testers validate the system with fewer test cases, such as testing ages 10 (under 18), 30 (18 to 65), and 70 (over 65), instead of testing every possible age value. This ensures that the system handles each partition correctly, without the need for exhaustive testing.

Currency Conversion Software: Equivalence partitioning can be applied in testing a currency conversion software. For example, the input range for converting US dollars to euros can be divided into partitions such as “zero or negative values,” “valid positive values,” and “invalid non-numeric values.” Test cases can be designed for each partition, like -5 (zero or negative values), 100 (valid positive values), and “abc” (invalid non-numeric values), to ensure that the software functions properly for each type of input.

E-commerce Website: In an e-commerce website, customers might need to select the quantity of items they want to purchase. The input range can be partitioned into different classes such as “zero items,” “one item,” and “two or more items.” Testers can use Equivalence Partitioning to test different scenarios using just one input from each partition. For example, a test case with a quantity of 0 (zero items), another test case with a quantity of 1 (one item), and a final test case with a quantity of 5 (two or more items) would verify the system’s behavior across various input scenarios.

Equivalence Partitioning FAQ

What is Equivalence Partitioning?

Equivalence Partitioning is a software testing technique used for creating test cases. In this method, input values are divided into various groups or partitions, which share common characteristics. The purpose is to minimize the number of test cases while still effectively testing the functionality of the system.

How does Equivalence Partitioning work?

Equivalence Partitioning works by identifying the valid and invalid input ranges for a given function and dividing them into separate groups. Then, test cases are created to cover each partition, ensuring that every possible value group is tested with minimal redundancy. This reduces the overall number of test cases required and improves testing efficiency.

What are the advantages of Equivalence Partitioning?

Equivalence Partitioning offers several advantages, such as reducing the number of test cases, improving testing efficiency, and increasing the level of confidence in finding defects. It allows testers to cover a wide range of inputs with fewer test cases, which saves time, effort, and resources while maintaining effective test coverage.

What are some examples of Equivalence Partitioning?

Some examples of Equivalence Partitioning include the following:
– Testing a system that accepts an age value between 18 and 65: The valid partition could be age values from 18 to 65, and the invalid partitions would be age values less than 18 and greater than 65.
– Testing a discount code input field for an e-commerce site: The valid partition may include various sets of valid discount codes, and the invalid partitions could contain discount codes with incorrect formats, expired codes, or codes that have already been used.

What is the difference between Equivalence Partitioning and Boundary Value Analysis?

Equivalence Partitioning and Boundary Value Analysis are both testing techniques, but they approach test case generation differently. Equivalence Partitioning divides input values into different groups (or partitions) and creates test cases for each group. On the other hand, Boundary Value Analysis focuses on testing the boundaries of each partition, including their boundaries, upper and lower limits, and immediate values around the boundary. While both methods are useful, Boundary Value Analysis is more suitable for identifying defects that occur at the edge of each partition.

Related Technology Terms

  • Boundary Value Analysis
  • Test Case Design
  • Input Domain Partitioning
  • Functional Testing
  • Software Quality Assurance

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