Why is Testing Important?


While the importance of testing is widely understood, this post lists some of the important points.

Testing is essential in a software development project due to several reasons. It helps keep the code quality high and enables the team to deliver value to the users and customers with confidence. The scope of testing is broader than just finding defects in the software. In this post, we’ll look at some reasons testing is essential.

Detecting Defects

One of the primary purposes of testing is to find and fix bugs or defects in the software. These could be simple coding errors or more complex issues, such as problems with the software’s logic or design. Coding errors are the obvious reason testing is needed, as there are almost always mistakes in the code. Finding bugs is not the only reason for testing but the most common one.

Validating Features

Testing helps confirm that the software’s features and functions work as intended and according to the requirements to ensure it delivers the expected value to its users. There are many occasions when a requirement has been defined in a way that made sense to the product owner or the business analyst, but the developers have interpreted it differently. Testing helps to validate that the software works as intended by asking the right questions about the requirements.

Verifying User Experience

Through testing, team members and stakeholders can ascertain whether the software provides a smooth and practical user experience. Factors such as user interface design, performance, accessibility, and responsiveness are all areas where different people in the organisation can take part and give feedback to ensure the software meets standards and expectations. User experience problems are not clear defects, and it’s possible that the behaviour was not even specified to that level. Still, it’s important to point out behaviour that’s not unusual for websites or applications. While not a substitute for user testing, testing can help to identify issues early in the process.

Preventing Problems

It is well-known that bugs are cheaper and easier to fix the earlier they are caught in the development process. This fact is one of the important realisations that led to the “shift left” approach, where the team (developers and testers) tests software as early as possible. Different team members use various tools and test types to achieve the goal, from unit testing by developers to end-to-end tests by (often) testers. Specific practices to help in this regard are Test-Driven Development (TDD) or Behaviour Driver Development (BDD), where tests are written before the code, helping to guide the coding process and prevent defects from being introduced in the first place. A wider range of team members, including the product owner and business analysts, can participate when using BDD, as the requirements are readable to non-developers.

Supporting Software Maintenance

As software is updated or enhanced over time, testing helps ensure that new changes don’t break existing functionality. Regression testing is crucial for maintaining the quality of the software over its lifetime. It also enables continuous delivery as the team can confidently deploy new software versions. This is an area where automated tests are required to ensure the team can deliver new software versions frequently, as running all tests manually every time a new version is released is not feasible.

Improving Confidence and Trust

Testing proves that the software works as intended, improving confidence among the project team, stakeholders, and users. Depending on the type of organisation and the types of practices used for software development inside the organisation, increasing confidence can be a crucial factor for a successful software project. For example, in digital transformation projects, the client organisation often uses extensive testing cycles at the end of the delivery process. Continuous delivery may raise questions about whether the team tested the software thoroughly enough. Building confidence and trust can help overcome these questions.

Legal and Compliance Requirements

In some industries, thorough testing is not just a matter of quality. It can also be a legal or compliance requirement in, for example, finance-related sectors. Testing helps ensure that the software meets all necessary regulations and standards.

Risk Mitigation

Software defects can lead to severe consequences, including financial losses, security breaches, and damage to a company’s reputation. Testing helps to mitigate these risks by catching defects before the software is released. It is common for the team to release software and monitor production errors afterwards to make sure everything works as planned. Monitoring is vital for any software project, but it is sometimes used instead of proper testing before the release. This is fine for non-critical websites as long as the risks are understood and accepted. However, for critical systems, testing is a must.


In short, testing is a vital part of the software development process that ensures the end product is reliable, user-friendly, and efficient. It brings value to the business, reduces the risk, and increases the satisfaction of the end users.