Regression Testing

Software developers use regression testing to confirm that a change in program code has not affected existing features. The effect tested for could either be adverse or measly.

A recent report by Forbes reveals a bug that took Google two years to fix. Despite the company having some of the best development teams around the world, bug fixing still became a nuisance. Currently, the fix has already been initiated by tech support but software developers have always been on the lookout of such after release bug shocks.

The only way to minimize or avoid any of the after release software bugs, is to put in place a seamless black box technique. Regression testing backdates and fixes software problems by executing unit codes repeatedly to make sure the on-going adjustment do not affect the software’s functionality.

Why do you Need Regression Testing

Regression testing is put in place to ensure that new implemented code works even better than old code. The system functionalities should be hailed in the new code as well as ensure that the system delivers results as per the software requirements.

Implementations of the software code could occur for various reasons and in many forms. It could be a bug fix, addition of a new feature, a software enhancement and better yet software integration. Regression testing is hectic but proves to be the best decision made in later stages of the software life cycle. You will note that many software development teams use the method as a way to achieve a system’s full functionality and most importantly; avoid nasty error shocks in future.

Software engineers often recommend that regression testing is done frequently along the software development life cycle. There are various instances upon which regression testing is hailed during the development of software. Such instances include;

  • Change in requirement, hence code modification
  • Detect Fixing
  • Additional features
  • Performance issues that need fixing

Types of Regression Testing

It is worth noting that regression testing is done during different phases of software development. Usually, it is during the test phases of the software. Therefore, this creates several types of regression testing for each different phase.

Unit Regression

This regression testing type is executed during the unit testing phase. The code in this phase is tested as a single unit. The approach for unit regression is lightweight, simple and could take a narrow-focused dimension. In fact, complex interactions between the code and various dependencies outside the unit code are briefly blocked.

Partial Regression

Code implementations during this phase, are made to interact with other parts of the existing code as a unit. Partial regression is executed immediately after impact analysis.  The main aim of this method is to ensure that the implemented software, functions as it should even in silos and after modification.

Complete Regression

Complete regression is usually carried in case there have been software updates, new features and modifications, as well as multiple changes to the executed code. Complete regression offers software developers to take on a comprehensive review of the software and get rid of any unforeseen errors that might occur in future. After the complete regression, software development teams could employ a kind of final regression testing to verify that lines of code have not be altered for a period of time. After the final regression, the final code version can then be deployed to the end use.


The need for regression testing goes hand in hand with the quality assurance. Software bugs could be a huge turn off to the end user, and employing testing techniques that weed out such problems earlier in the development stage is of utmost importance.