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The 7 Principles Behind Effective Software Testing

Updated: Oct 5, 2023

Kazeem Razaq @K.Razaq / 5:00 PM EDT. November 4, 2022.


Software testing is a vital part of the software development process. It helps ensure that your code works as expected, which saves time and money and can even reduce legal liability. But when you hear people talk about software testing, they often seem to think of testing as something that happens after the software has been developed—if at all. This isn't accurate!

Software testing is an important process in the software development life cycle. It ensures that your application meets both practical and functional requirements, maintains the integrity of your codebase, and ensures the user-friendliness of your website. However, software testing is often considered by stakeholders to be a tedious, time-consuming and expensive process. This is because software testing is often treated as a second-class citizen in the development or testing process. In this article, we will look at seven principles that can improve your understanding of software testing so that it becomes a valued source of information for projects at all stages of their lifecycle.

What is the QA testing life cycle?

QA testing life cycle is the process of how a product, service or software is developed, tested and released to the market. QA testing helps in preventing errors and bugs from entering the final release.

QA Testing Life Cycle Processes:

Pre-Testing: This process is usually done in advance of development and involves analysis of requirements, design documents, design diagrams and wireframes. This helps in identifying potential issues before they are turned into actual software code.

Build & Test: As soon as the software is ready for testing, it goes through this phase where it’s tested by various users and testers who use it on their own to identify any issues with the software. After this stage, bugs are fixed/removed and any additional changes are made based on user feedback.

Post-Testing: Once all bugs have been identified and fixed, it goes through this phase where it’s tested again by different groups of testers who use it on their own for various scenarios (like production environment) and make sure that there aren’t any issues left behind after all these changes were made.


1 First principle: Exhaustive testing is impossible

The first principle of effective software testing is that you cannot exhaustively test everything. You simply have to prioritise what needs to be tested and focus on those areas first.

Exhaustive testing is impossible because it would require too much time and resources, even if you had all the time in the world. Instead, we need to make sure that we’re focusing our limited resources where they will have maximum impact on solving problems faster. That usually means focusing on high-risk areas first: things that could potentially cause serious problems with our product or services if left unchecked by developers or testers alike (or even just users).

If I were going to test every possible scenario imaginable in order to prevent bugs from occurring during development stages then I would never get anything else done while doing so! Instead of wasting weeks/months overthinking how best to fit certain scenarios into a single test case which might not even work correctly due to its own lacklustre design choices which leads towards poor results downstream.

2 Second principle: Early testing

Testing early helps you avoid costly bugs. It also helps you identify the right approach to testing and potential problems in your code.

3 Third principle: Choosing good test cases is as important as creating them.

We've already seen that a good test case should be chosen based on its value. But what does this actually mean?

A good test case is one that covers important features and functions of your software, not just because it's easy to write. It should also involve some kind of user interaction, or fail if the feature doesn't work. This means that you need to consider what kind of behaviour your users are likely to exhibit when interacting with your product (for example, whether they will perform actions in a particular order).

If you have time and resources available, then consider using “costly” methods such as manual testing or penetration testing where possible – these can add real value in terms of identifying bugs which might otherwise go unnoticed due to lack of coverage by automated tests alone!


4 Fourth principle: Defect clustering

Defect clustering is when a group of defects are found in the same area of the code. This can be caused by poor design or even bad testing. Depending on what caused it, defect clustering can also occur if there are bugs that cause your software to crash repeatedly.

5 Fifth principle: Pesticide paradox

The fifth principle is called Pesticide Paradox. This one is so simple and yet so powerful that it can be applied to almost any situation in life: the more you spray, the more pests you get; the more chemicals you use (even if it's for your own good), the more damage they do; and so on.

Testing software has a similar effect on your bug count. The more tests that are run against old code or new features at once, the greater their chance of uncovering bugs—and this leads us directly to our sixth principle:

6 Sixth principle: Testing is context-dependent

Testing is not just a matter of running the software in a lab or on a computer. It's also important to test our products in different environments, including real-world scenarios. This can help us understand how our software will perform under different conditions and circumstances, which can make it easier to identify bugs early on in development.

7 Software testing involves tradeoffs and careful thought about what's worth testing.


Software testing is an iterative process, so you have to decide what to test, how much of it to test and how you'll test it. This can be a challenge because there are tradeoffs in every decision:

  • You can't test everything. The more code you write, the more bugs will be created; but if you don't write any code at all then your project won't get done and that may force management into making decisions about whether or not they want something built at all!

  • Testing takes time and effort on both sides (your side as a tester and their side as a developer). If one person does both roles then they'll spend less time with each project since they're doing both jobs instead of just one job; however, this also makes things harder for them because they need someone else who's good at being bad (i.e., testing).

If you want to learn more about software testing and obtain cutting-edge, high-quality training, and certifications, visit BusyQA. We offer strong online training courses as well as certifications to help you land your dream career as a software tester. Our software testing course covers Manual, Mobile, Web Service, SQL, and Automation. Our students have gone on to work for Canada's top 100 companies and you can be next.

Click here to get started.

You can also read about the 9 best software testing certifications and the five common challenges facing software testers.


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