What is Exhaustive Testing? (Techniques & Comparison)

Global Market Insights Inc predicts the software testing market will hit $70 Billion by 2030. The surging demand for mobile apps among consumers and the growing requirement for modern customer interfaces will further enhance testing uptake. 

Testers try their best to test an app comprehensively, however, still some bugs remain in the system, which results in errors in the system. To mitigate such an issue, an app goes through exhaustive testing, where a QA team tries all possible test inputs for testing the system, covering every likely test scenario. 

Let’s learn more about this type of testing which is a time-taking method, but the result is high value.

What is Exhaustive Testing?

Exhaustive testing, also called brute force testing or complete testing is a software testing technique in which all possible combinations of scenarios and inputs are tested to confirm that a software system functions properly under every possible situation.  

Why is Exhaustive Testing important?

Exhaustive testing is significant as it aims to test all possible scenarios and input combinations to make certain that a software system functions suitably under all possible circumstances. This assists to detect defects or bugs that might not be caught by other testing approaches.

• Exhaustive testing is particularly significant in safety-critical systems, where the consequences of a failure or defect can be severe, such as in aviation systems, or nuclear power plants. 
• In such cases, it is critical to ensure the system functions properly under each possible condition to prevent catastrophic consequences. 
• It is crucial to note that exhaustive testing is often impossible or impractical in numerous software systems because of the huge number of possible input combinations and the restricted resources accessible for testing.

Types of Exhaustive Testing

Some of the commonly used forms of exhaustive testing are:

1. Combinatorial Testing: This method of exhaustive testing is based on the observation that the collaboration of two input parameters causes the majority of defects in software systems.
2. Boundary Value Analysis: Boundary Value Analysis is a type of exhaustive testing that assists to identify defects that may happen at the boundary values.
3. Equivalence Partitioning: It divides the input values into equivalent partitions or groups and tests one value from an individual partition to confirm that all input values have been tested. 
4. Decision Table Testing: This type of exhaustive testing uses a tabular to represent every possible blend of input conditions & the corresponding output actions. 
5. State Transition Testing: This testing focuses on testing the software system’s behavior as it transitions from one state to another. 

Steps involved in Exhaustive Testing

The following are the 7 steps included in exhaustive testing:

1. Detect Input Parameters: The first phase is to detect all the input parameters that can affect the software system’s behavior. This can include system inputs, environmental inputs, and user inputs.
2. Determine Input Ranges: For every input parameter, determine the set of values it can take. This comprises identifying the maximum and minimum values & any other constraints or necessities for the input parameter.
3. Generate Test Cases: Once the input ranges and parameters have been recognized, generate test cases covering every possible input amalgamation. This can be done using boundary value analysis, combinatorial testing, decision table testing, equivalence partitioning, and state transition testing.
4. Execute Test Cases: Execute the created test cases for testing the software system’s behavior under every possible input combination. This might involve running the testing several times with diverse input combinations. 
5. Analyze Test Results: Analyze the outcomes of the tests to detect any issues or defects with the software system. This may include comparing the actual outcomes with the projected results for every test case. 
6. Debug Defects: If defects are recognized, debug them & retest the affected zones of the software system to ensure that the defects have been resolved.
7. Report Findings: Ultimately, report the testing findings to the relevant stakeholders, counting any recognized defects and the steps taken to solve them.

Top 6 Challenges in Exhaustive Testing

1. Limited Scope: Exhaustive testing might not cover all possible scenarios and input combinations because of the vast number of potential input values. This can result in some flaws not being identified or missed during testing. 
2. Time & Resource Intensive: Needs a noteworthy amount of time & resources to test all possible scenarios and input combinations. This can be impractical for complex and large software systems. 
3. Overfitting: This might result in overfitting, where the test is focused on particular input scenarios and combinations rather than the software’s overall functionality. 
4. Maintenance: Maintaining and upgrading exhaustive test cases can be perplexing, especially when modifications are made to the software system. 
5. Redundancy: Some test cases in the exhaustive tests might be redundant and not add value to the complete testing effort. This can result in pointless testing and consume extra resources without substantial benefits.
6. False Confidence: The all-inclusive nature of testing can create a false sense of confidence that all possible input scenarios and combinations have been tested, resulting in the assumption that the software system is error-free.

Why is complete Exhaustive Testing not possible?

Exhaustive Testing means testing the app as a whole and covering all possible things but it is not possible due to several reasons:

• Design issues
• Time-consuming
• Manual testing
• Complex
• Different users
• Time constraint

Example of Exhaustive testing

Let’s consider a simple instance of an exhaustive test for a login form that has two distinct input fields: password and username.

– Let us assume the username field accepts alphanumeric characters & the password field accepts a blend of numbers, letters, and special characters; exhaustive testing would include testing all possible blends of valid & invalid inputs for both fields.

For instance, if the username field accepts up to 10 characters and the password field accepts up to eight characters, the total no. of possible input combo would be:

• Username: 62^1 + 62^2 + … + 62^10 = 839,299,365,868,340,224 probable blends.
• Password: 94^1 + 94^2 + … + 94^8 = 6,634,204,312,890,625 probable blends.

In practice, varied testing techniques such as equivalence partitioning, boundary value analysis, and combinatorial testing can be used to lessen the no. of test cases needed for exhaustive testing while still attaining a high automation test coverage.

Advantages of Exhaustive Testing

Exhaustive testing is a testing approach that aims to test all possible combinations of scenarios, paths, and inputs of a system under testing. Some benefits of exhaustive testing that are worth considering are as follows:

• High Test Coverage: Exhaustive testing makes sure that all possible combinations of scenarios, inputs, and paths are well-tested, which results in the maximum test coverage. This means that a higher percentage of flaws can be found & fixed before the item is released.
• Increased Confidence: Exhaustive testing gives software developers and testers enhanced confidence that the product has been well-tested and has no undiscovered defects. 
• Improved Quality: This testing can enhance the product’s quality by finding flaws that may not be discovered through different testing approaches.
• Great Customer Satisfaction: By finding & fixing defects before the product is launched, customer satisfaction can be enhanced. This can result in increased consumer loyalty and repeat business.

Limitations of Exhaustive Testing

• Time-Consuming: It can be extremely time-consuming, especially for complex systems with many possible input combinations. 
• High Cost: It requires a significant amount of resources, including testing tools, personnel, and hardware, which can augment the complete cost of the project.
• Infeasible: In a few cases, it might not be feasible, chiefly for intricate systems with many scenarios and inputs.  
• Lack of Real-World Scenarios: Cannot cover all real-world scenarios. Even with exhaustive tests, there is no guarantee that all probable scenarios will be covered, which may result in flaws.
• Limited Effectiveness:  Might not be adequate to detect certain kinds of defects, such as defects concerning user experience or environmental factors.

Strategies for Exhaustive Testing

• Boundary Value Analysis: This technique aims to identify any errors that may occur at the boundaries of the input range.
• Use of Test Automation Tools: Test automation tools can be very beneficial to conduct exhaustive testing. Using automated testing tools, QA teams can achieve comprehensive test coverage, enhance testing competence, and deliver top-quality software.
• Combinatorial Testing: Combinatorial testing is useful when there are multiple input variables, and testing every combination is not feasible. It can considerably reduce the multiple test cases required to attain the desired level of test coverage.
• Equivalence Partitioning: The objective is to minimize the number of test cases needed while maximizing the test coverage. 

But, it is essential to note that equivalence partitioning alone is not a strategy. Different testing techniques, such as combinatorial testing and boundary value analysis, can be used in conjunction with equivalence partitioning to achieve exhaustive testing.

You can also automate your formal test process by choosing BrowserStack, which can minimize time and effort. Access the robust testing infrastructure to ease your browser and app tests. 

Try BrowserStack now

Exhaustive Testing vs Exploratory Testing 

Here’s a comparison between Exhaustive Testing and Exploratory Testing:

Exhaustive Testing vs Ad-hoc Testing 

Here’s a comparison between Exhaustive Testing and Ad-hoc Testing:

In a Nutshell,

While Exhaustive Testing is a comprehensive approach, it may not always be suitable or practical for big input domains or complicated systems. In such cases, other testing strategies such as Exploratory, Ad-hoc, and Random Testing can be used in conjunction.

Ultimately, a well-planned and executed testing strategy, a pristine platform like Browserstack, and a blend of different testing techniques, can help guarantee that software is of superior quality and meets the required standards.

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