Seems obvious but... better tests can help improve software quality
Tags: webdev, testing, beginners, productivity
Published: 2023-05-11 18:23:26

Testing is an indispensable part of the development process, particularly when it comes to business-critical systems. Despite the fact that testing can be costly, it accounts for a significant portion of overall development expenses. Testers must still write test cases based on requirement specifications, despite the increasing usage of automated testing technologies. This has become a creative endeavor for many, and software test engineering has evolved into a specialized field that may be more complicated than programming. It's important to remember that some customers regard testing as a parallel software project, which can lead to a sense of duplicated effort.

![Imagine of the V model, one of the classic existing processes for software development](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/fxxscrslb5u8z9qs4agk.png)

The classic approach to test design, where we write test cases by hand, poses many challenges. Some are listed below:

- High effort: Creating tests in the traditional manner can prove to be quite a challenge. It requires a significant amount of time, energy, and resources to develop a thorough test plan that covers all aspects. This becomes especially apparent for intricate systems where the number of test cases needed can be extensive. Generating all of these test cases manually can feel overwhelming, and it can also be quite costly. Fortunately, with the aid of modern technology, we can streamline this process, making it more efficient and budget-friendly.

- Incomplete test coverage: From my experience, it seems that conventional test design may not always be sufficient in testing systems comprehensively. Consequently, it can be challenging to determine the extent to which a system has been covered. This can give rise to concerns regarding the overall quality and precision of the systems delivered.

- Difficult to maintain: When classic test design specifications change, testers have to do a lot more work to update the test cases. This can take a long time and make the tests less accurate. But, with the right tools and methods, it's possible to keep the tests accurate and even improve them over time.

## Cost-Effective Testing and the Test Design Phase

Contrary to popular belief, spending more time and money on testing does not always result in better software quality. In fact, there are two key factors in the software development process that can be adjusted: testing and debugging. 

It's important to note that neither of these factors follow a linear pattern. As a team seeks greater confidence in the software's quality, the cost of testing increases. Although initially increasing the number of tests has a linear impact, it eventually reaches a point where combinatorial methods must be utilized to test the input domain elements. Even with all these extra tests, some bugs may remain undetected, and the coverage may not noticeably increase. This makes it less beneficial to spend time designing or running the tests. 

Another important factor to consider is the cost of bug fixing. Fixing a bug later in the software's lifecycle is far more expensive, and the cost of correction increases exponentially with time. By identifying defects earlier in the process, we can significantly reduce the total cost of correction.

![A graphic showing the project cost versus project schedule: at some point, changes become too expensive](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/nb8j13t7e1jbc9y2bmzx.png)

When it comes to software releases, many people wonder if cost optimization ensures good code quality. Unfortunately, focusing solely on test execution for defect detection due to ineffective test design can increase costs and leave many bugs undetected. Just achieving an optimum point doesn't guarantee acceptable quality.

The key is to use highly efficient test design techniques to increase the ratio of detected bugs, resulting in acceptable quality at the optimum point. While the level of test design varies by feature, strategies can be implemented to decrease testing costs while maintaining quality. It's important to consider both factors together, using an efficient test design technique to reduce SDLC costs and achieve acceptable code quality.

Simply put, riskier and more complex features have higher bug-fixing costs if testing efforts remain unchanged. Delaying bug fixing until later in the lifecycle can reduce code quality at release. Thus, thorough testing with higher costs is necessary for these features.