Software development and maintenance is an ongoing process. It has different phases,including, but not limited to, error corrections, code optimization, new functionality development, bug fixing, so on and so forth. As you can assume,these activities result in the change of existing code. In the software, different modules are directly or indirectly connected with each other. Thus, any change in the code of one module may adversely affect one or more other modules. This creates a need for consistent software testing. The regression testing is a process of assuring that the code change of one module hasn’t affected any other module adversely.

The regression testing can be full or partial. The selection of full or partial regression testing is dependent on various factors. Some of them are listed below:

• Business impact
• Frequently used functionalities
• Critically used functionalities
• Complex functionality
• Budget
• And more

Professional software testing companies offer regression testing services that ensure maximum coverage in minimum possible test cases. The software testing experts select the test cases using various techniques. The most commonly used techniques in the regression testing are listed below:
1. Retest all
2. Selective Regression Test
3. Test Prioritization
a. General
b. Version specific
4. Hybrid

Regression testing is different than retesting the software. In regression testing, the software testing professional uses the same test cases, which have already been executed. This easy-looking task is tough because the software testing company or professional need to ensure that the selected test cases provide maximum coverage with minimum investment of time and money. Also, it has to be assured that nothing is left untouched during the test.

When to use regression testing?
Regression testing can be an ongoing test process which needs to be carried out on the occurrence of one or more scenarios from the below mentioned list:
• After fixing a defect / bug
• After fixing the performance issue
• After making aesthetic changes
• After adding new features
• After replacing existing code
• In case of a change of requirements necessitating a code change

Key benefits of regression testing:

• Assures the highest quality of software
• Assures the code change doesn’t adversely affect other modules
• Assures the bug found earlier are not reproduced
• Keep brand credibility intact by maintaining the quality of the product

Regression testing tools:

The software testing companies and professionals use an amalgamation of automation and manual testing to perform regression testing. Different companies use different tools. Some of the most commonly used tools for regression testing are listed below:

• Selenium
• actiWate
• Rational Functional Tester (RFT)
• Quick Test Professional (QTP)
• SilkTest
• TimeShiftX
• Winrunner

Author's Bio: 

MArk is working in the Top QA Company that offers the best QA services as well as software testing services to benefit its customers across the world.