How is Black Box and White Box Testing defined, and can they be done by automated testing?

Automated testing is one of the best software testing techniques where test cases are performed using special automated testing software tools. There are different types of automation tests you can use in your organization depending on the prevailing needs and the nature of operations. Black box testing is one of the high-level tests that focus on the system’s overall behavior.

On the other hand, white box testing checks the internal functioning of the whole system. There are several reasons why most organizations prefer test automation to manual testing. One of the main reasons is coverage,as you can cover more test cases with automated testing compared to manual testing. This is because most test cases can be performed 24/7 using different automation test tools. Tools for automation testing are less prone to errors than the manual testing approach, which highly depends on the human ability to create different test scripts. This implies you will be able to release your software product to the market faster than when using the manual testing approach.

Black box testing

As stated above, the functionalities of the software product in Black Box Testing are tested with little to no knowledge of the internal code structure, internal paths, and implementation details. This testing primarily focuses on the software product’s input and output, mainly on the software requirements and disparate specifications. It’s often referred to as behavioral testing.

How black box testing is done

You can follow different steps to carry out black box testing on your software product. First, examine all the system requirements and specifications. Then, choose the valid inputs by checking whether the SUT can process them correctly. You can also choose other invalid inputs to verify that the SUT can detect them.

After that, determine the expected outputs for all the inputs. Construct test cases with selected inputs and execute them. Finally, compare the actual outputs with the selected outputs, fix the defects, and re-test the fixed test cases.

Black box testing techniques

There are several types of black box testing techniques you can use in your organization to test your software product, and they include:

Equivalence partitioning

For the equivalence testing, you will have to divide the possible inputs into different groups and test only one of the inputs from each group. This black box testing technique tries to define test cases that uncover different classes of errors. And this means you will reduce the total number of test cases you need to develop.

Decision table testing

This testing is used to test the system’s behavior for disparate input combinations. It’s usually a systematic approach whereby the different input combinations and system behaviors are captured in tabular form. Decision table testing is also known as the cause-effect table.

Boundary value analysis

Boundary value analysis is a testing technique where test cases are designed to include particular representatives of the boundary values in the range. This testing technique focuses on whether the value you are entering is producing the correct output or not. Boundary values are the values that usually contain the lower and the upper limit of a variable.

White box testing

White box testing focuses on the software product’s internal structures or working instead of its functionality. To perform this testing, you must have internal knowledge of the whole system and excellent programming skills. Ensure that you read the software requirements, specifications, and the design test case before you execute specific code paths through the code.

This type of testing is usually done at the software testing’s integration, unit, and system level. It’s advisable to use a code coverage tool as it’s less expensive and will help speed up the whole process of the White Box Testing.

How to perform white box testing

There are two basic white box testing steps that you can use when testing an application.

Understand the source code

Before you start testing, you need to learn and understand the software product source code. Since white box testing involves testing the internal working of the software product, you will also need excellent programming skills specifically for the software products you are testing.

If you are working with different teams, you must ensure that each of them is well versed in secure coding practices. Remember that security is the primary objective of software testing.

Create test cases and execute

Creating test cases and executing them is the second step of white box testing. In this case, you are testing the software’s source code for the proper structure and flow. More code is highly needed to test the application’s source code. Develop little tests for every process in the application. You will need great coding skills and intimate programming knowledge to perform this testing effectively. 


Both black box testing and white box testing are essential in testing the overall functionality of the software product. With the black box testing, you will understand the test functionalities from a behavioral point of view. On the other hand, white box testing will help you test the internal structures of the software product.

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