Are You Using These 5 Black Box Testing Techniques? If Not, Your Software May Be At Risk!

When I say “work smarter, not harder”, what I mean is that I want to find ways to optimize my approach to software testing. Instead of just putting in more hours or more effort, I want to focus on working more intelligently. This means using techniques and strategies that allow me to get the best results with the least amount of work.

One technique that I’ve found to be particularly helpful is black box testing. This approach involves testing the application from the perspective of an external user, without having access to the internal code or workings of the application. By doing this, we can identify potential issues that users might encounter, without getting bogged down in the technical details of the application.

Also, check 10 Essential Tips for Effective Penetration Testing

By using black box testing techniques to create test cases, we can ensure that we’re covering all the important functionalities of the application, without wasting time on unnecessary tests. This can save a lot of time and effort, while still allowing us to uncover critical bugs that could have serious consequences if they go unnoticed.

Overall, I think it’s really important to be thoughtful and strategic in our approach to software testing. By working smarter, not harder, we can achieve better results and improve the quality of the applications we’re testing.

What Is Black Box Testing?

Hey there! I’d love to explain black box testing to you in a friendly and approachable way. Essentially, black box testing is a type of software testing where I don’t have access to the internal structure of the app that I’m testing. Instead, I can only see the inputs and outputs of the system, and I use this information to test the functionality of the software based on the requirements specifications.

It’s important to note that black box testing only covers the external functionality of the software, and doesn’t check the internal workings of the source code. That’s why it’s sometimes referred to as “behavioral testing”. To make sure that the software is fully tested and free of defects, it’s a good idea to use black box testing in combination with white box testing, which focuses on testing the internal code.

By using both types of testing, we can get a more complete picture of how the software is working, and have greater confidence in its overall quality. So, if you’re ever in doubt about which type of testing to use, remember that it’s always a good idea to include both black box and white box testing in your testing strategy.

Also, check As a Tester You Should Know: What is Kobiton?

5 Types Of Black Box Testing Techniques

When it comes to software testing, I’ve found that using black box testing techniques can really help to increase test coverage while reducing the number of test cases needed. By carefully selecting the right test data, I can create a small number of tests that still provide a high level of coverage across the application.

The great thing about these techniques is that they can be used at all testing levels, from unit testing to integration testing and system testing, as well as functional and non-functional testing. This means that no matter what type of testing I’m doing, I can use these techniques to make my testing more efficient and effective.

So if you’re ever struggling to create enough test cases to cover all the important functionality of your application, consider trying out some of these black box testing techniques. You might be surprised at how much more coverage you can achieve with fewer tests!

Also, check Why Am I Not Getting Interview Calls?

1. Equivalence Partitioning

I’ve learned a really cool technique called equivalence class partitioning that can help you create more efficient and effective software testing! Essentially, the technique involves dividing all the possible inputs into different equivalence classes, based on functional or non-functional requirements, such as data types, ranges, and relationships between input values.

The goal is to find and test a representative set of inputs from each class that should give out the same output. By testing only one value from each class, you can significantly reduce the number of test cases that need to be created and executed, while still providing good coverage.

It’s important to include invalid inputs in the equivalence classes, as well, to cover negative test scenarios. In my experience, testing invalid inputs can be particularly helpful in finding defects.

Overall, using equivalence class partitioning is a smart way to make your testing more efficient and effective, while still ensuring that your application is thoroughly tested. So why not give it a try and see how it can help you streamline your testing process!

Also, check Globalization Testing: Key Considerations for International Expansion

Let’s look at an example:

You have an optional field that only allows integer values between 1 and 10. You would have the following equivalence classes:

• no value (valid partition)
• values between 1 and 10 (valid partition)
• values smaller than 1 (invalid partition)
• values higher than 10 (invalid partition)

So you would need only 4 test cases — 1 for each partition. There is no added value from retesting the same partition with multiple values-if you tested for value 5, you would get the same results for values 4, 8, and so on.

2. Boundary Value Analysis

Have you heard of boundary analysis in software testing? It’s a technique that I find really helpful! Essentially, boundary analysis involves testing input values that are at or near the edge or “boundary” of the program’s input domain. These values are more likely to cause errors or unexpected behavior because they involve special or edge cases that the program may not have been designed to handle properly.

For example, if you’re testing a program that accepts integers between 1 and 100, the boundary values would be 1, 100, and all the values just outside the range, such as 0 and 101. By testing these boundary values, you can make sure that your program handles special cases and edge cases correctly.

Overall, boundary analysis is a helpful technique for making sure that your software testing is comprehensive and thorough. So why not give it a try and see how it can help you find and fix potential issues before they become bigger problems!

The two types of boundary testing are:

• Inner Boundary Testing: focuses on the input values that are just inside the edge of the input domain, such as the minimum and maximum values that are allowed.
• Outer Boundary Testing: focuses on the input values that are just outside the edge of the input domain, such as values that are slightly above or below the minimum and maximum allowed values.

Boundary analysis is an important technique for finding errors and ensuring that a program behaves correctly for all inputs, not just those in the middle of the input domain. This can help to identify and fix bugs that might otherwise go unnoticed.

Also, check What is End-to-End Testing? E2E Testing Full Guide

3. Decision Table Testing

In decision table testing, we test the logic and behavior of software when multiple conditions are available. It is a way of representing the relationships between inputs and outputs in a tabular format. The table typically has columns for conditions, and rows for the different combinations. For each row, you need to create a specific test case. The expected output for the test case should also be included in the table.

Let’s imagine a software requirement example where this technique can be applied: an app that calculates the cost of a purchase based on the item, quantity, and shipping method:

Source — The QA Lead

In this example, the Item, Quantity, and Shipping Method are the inputs, and the Cost is the output. The table shows all the possible combinations of inputs and the corresponding output in each case. By using this table, you can quickly identify the test cases and their expected results, making it easy to test and verify the available combinations.

Decision table testing is useful when a program has multiple inputs and conditions that interact with each other in complex ways. By breaking down the inputs and conditions into a table, it becomes easier to identify and test all the possible combinations and variations.

Also, check xPath Locators Cheatsheet PDF Free Download

4. State Transition Testing

When I use state transition testing, I focus on the different states or modes of a program and how it behaves when transitioning between them. For example, when testing an e-commerce website, I would look at the different stages a customer goes through when placing an order, such as adding items to their cart, entering payment and shipping information, and completing the order. By identifying all possible states and transitions, I can create test cases to make sure the program behaves correctly at each stage and makes valid transitions between them.

The states in this example would be:

• Browsing products
• Adding items to cart
• Checking out
• Entering payment and shipping details
• Order confirmation

The transitions between these states would be:

• Browsing products -> Adding items to cart
• Adding items to cart -> Checking out
• Checking out -> Entering payment and shipping details
• Entering payment and shipping details -> Order confirmation

Source — The QA Lead

This technique helps to identify and test all the possible paths that a user can take through the system, and can help to find and fix bugs related to specific flows. State transition testing is particularly useful for testing systems with complex interactions, such as financial systems, e-commerce systems, or systems that control physical devices.

Also, check 100+ Java Programs with Output PDF Free Download

5. Pairwise Testing

Pairwise testing is a black box testing technique used to create test cases to cover all possible pairs of combinations of input values for a given set of parameters. It is used when the available number of inputs is high, which would make it extremely difficult to test all possible combinations between all of them.

Let’s say we have an app with 3 fields: A, B, and C. Each field can accept 3 possible values: 1, 2, or 3.

With traditional testing methods, we would have to test 27 (3³) possible combinations of inputs individually, to validate all possible combinations. This would be extremely time-consuming and inefficient.

Source — The QA Lead

With pairwise testing, you can identify use cases that cover all possible unique combinations of inputs. This would look something like this:

Source — The QA Lead

As you can see, the number of tests has been drastically reduced, from 27 to 9. The test coverage hasn’t changed, we are still ensuring that all possible combinations of values are taken into account.

There are several pairwise testing tools available to use. I’ll list below some examples:

• AllPairs: A tool for creating pairwise test cases based on user-specified parameter lists and constraints. It is available in both open-source and commercial versions.
• PICT (Pairwise Independent Combinatorial Testing): A tool that uses a genetic algorithm to generate pairwise test cases. It is available as an open-source tool.
• SmartBear TestComplete: A commercial test automation tool that includes built-in support for pairwise testing.
• Pairwise Test Case Generator: An open-source tool that is available on GitHub and can be used to generate pairwise test cases.
• Pairwise testing can also be generated using Excel or OpenOffice Calc using macros or plugins to generate your test cases.

These are just a few examples, and there may be other tools available as well. I recommend you research and evaluate the different options available and see which tool works best for your specific needs and requirements.

Also, check CICD Pipeline PDF Free Download

Final Thoughts:

In my experience, using these techniques can really help to achieve good coverage at any stage of the software development life cycle. However, it’s important to keep in mind that they’re not the only testing techniques available. Exploratory testing, error-guessing, compatibility testing, usability testing, and other types of testing can also be very useful.

If the resulting test cases end up in the regression testing suite, automating them can save time and increase efficiency. For UI tests, you may want to consider using tools like Selenium, Cypress, and Appium, while for API testing, the development team can write integration tests, or you can use tools like Postman.

If you’re interested in learning more about quality assurance and testing, I recommend subscribing to Software Testing Sapiens newsletter. This way, you’ll always be up-to-date with the latest content and tutorials.

Originally published at https://www.softwaretestingsapiens.com.