Serena Gray

Jul 14, 2021

6 min read

Beginner’s Guide to Regression Testing

Regression is a problem in the software industry. Regression is when you solve a problem and then discover new problems that have been created by an update. Regression has become a bigger problem with the rise of big data. The Intel Meltdown/Spectre issue at the start of the year is something that we all recall. The attempts by Intel and AMD to fix the problems ended in disaster.

This common problem can be solved by regression testing. What is regression testing? How can it benefit your business? Continue reading to find out more.

Software testing

Let’s start by looking at the two types of software testing that are used to understand regression testing.

Regression testing falls within the scope of BlackBox testing.

What’s regression testing?

This testing looks for software regressions. Regressions are when software is used to solve a problem. This could take the form of:

Regression testing ensures that:

This is not intended to test the action. It doesn’t guarantee that the update will work as planned, but it won’t have any unexpected consequences.

Testing takes place after an action, but before the action is implemented at the organizational level. We’ll discuss the types of tests that affect the timing of testing.

Regression testing (Do small changes need to be tested)?

Regression testing may not be necessary for minor changes, but it is important to remember that some people don’t believe so. Some believe that testing is only necessary for essential functions. Other stuff doesn’t matter as long as they function.

Yes. Regression testing can be used for many reasons:

Even minor software updates can cause serious problems. AT&T spent millions in 1990 to restore service after a minor update caused a network downfall. Learn from their mistakes. Do not assume that minor changes won’t have a major impact on your company.

Which change types are subject to regression testing?

There four major changes that need regression testing.

Regression testing

Regression testing involves repeatedly running code and seeing the results. You can execute the code in different ways depending on the effect it might have.

These are the most popular types of testing.

Corrective regression testing

Corrective testing is recommended if there have been no modifications to the product’s specifications. This type of testing is quick and efficient because it uses pre-existing test cases.

Retest All Regression Testing

This type of test retests all aspects of a product. It also reuses all test cases even if modifications or changes are not made. It is not the best way to make small changes to products.

Unit Regression

This method treats code as one unit. Unit regression occurs before integration and blocks interactions that extend beyond the code.

Partial Regression

This type integrates the unit of code that was tested in unit regression with the pre-existing codes. The software is tested to see if the code changes allow it to work as intended.

Complete Regression

Testers can view the entire picture by integrating both pre-existing and new code. The complete system view is available to developers. If the modified or added code has a significant impact on the roots, complete regression is required.

This type of testing is also required if you are making large changes to the code.

Regression testing

After you have written the modified code or new code there are some steps you will need to follow.

Perform a smoke and mental health test. This is not a trip to the psychiatrist’s (although it might be necessary if your new code causes problems). These tests are used to confirm the stability of your program before you go to regression testing.

At this stage, you are not looking for bugs and glitches. This is a test to make sure your system doesn’t crash when you start it.

Next, analyse the requirements for code. Most bugs are reported because of last-minute code changes. To ensure that your new build meets users’ needs, you will need to thoroughly analyse it before it is added.

To determine which type of regression testing you will need, look at the test cases. Before you start, you need to determine if you will need partial, complete, or unit regression testing.

Finally, analyse the usage patterns of your company and identify when software is most used. This is the time to schedule the test and make sure that the software is thoroughly tested before it’s released.

Depending on the needs of your company, you can also use automation to test your programs.

Regression testing

Let’s take a look at two common problems companies face when testing for regression and the solutions we have to them:

Regression testing can be too costly

It’s hard to justify the cost of testing a program multiple times during a build/update. Why should a company test something they haven’t tested before?

Although this concern is valid, it’s not difficult to address. Regression testing is more expensive than the cost of a critical piece of software breaking down, especially if it affects your ability to communicate effectively with customers. Not only does downtime affect your sales but also your reputation.

Any problem that testing catches can be avoided.

Maintenance & Optimization

You might have to make modifications to existing regression test suites when you make changes. You might need to modify, add, or remove test cases. This will take up additional time and place extra stress on development teams.

Many companies don’t run regression tests because of this problem. It is a waste of time to optimize and maintain suites compared to the time required to fix and find software issues after an update.

Your development team is not the only one that may be affected. Your team may lose valuable tools that impact customer service. You could save money and stress by investing a little more time and energy now.


With this short introduction, I hope you have understood the importance and benefits of regression testing. Without it, your reputation and that of your staff could be at stake.