Wednesday, 8 March 2017

Regression Testing - A crucial step for the success of application development and upgrades

Oniyosys conducts regression testing, where previously run tests are re-conducted to avoid the emergence of old/new software bugs or regressions that typically come back when major code or program modifications/maintenance are done.

Let’s talk about our Regression Testing for better understanding :

When any modification or changes are done to the application or even when any small change is done to the code then it can bring unexpected issues. Along with the new changes, it becomes very important to test whether the existing functionality is intact or not. This can be achieved by doing the regression testing.

Types of Regression testing techniques:

We have four types of regression testing techniques. They are as follows:

1) Corrective Regression Testing: Corrective regression testing can be used when there is no change in the specifications and test cases can be reused.

2) Progressive Regression Testing: Progressive regression testing is used when the modifications are done in the specifications and new test cases are designed.

3) Retest-All Strategy: The retest-all strategy is very tedious and time-consuming because here we reuse all test which results in the execution of unnecessary test cases. When any small modification or change is done to the application then this strategy is not useful.

4) Selective Strategy: In selective strategy, we use a subset of the existing test cases to cut down the retesting effort and cost. If any changes are done to the program entities, e.g. functions, variables etc., then a test unit must be rerun. Here the difficult part is to find out the dependencies between a test case and the program entities it covers.

When to use it:

Regression testing is used when:

  • Any new feature is added
  • Any enhancement is done
  • Any bug is fixed
  • Any performance related issue is fixed

Advantages of Regression testing:

  • It helps us to make sure that any changes like bug fixes or any enhancements to the module or application have not impacted the existing tested code.
  • It ensures that the bugs found earlier are NOT repeatable.
  • Regression testing can be done by using the automation tools
  • It helps in improving the quality of the product.

Regression Testing Techniques

Software maintenance is an activity which includes enhancements, error corrections, optimization and deletion of existing features. These modifications may cause the system to work incorrectly. Therefore, Regression Testing becomes necessary. Regression Testing can be carried out using following techniques:

Retest All
This is one of the methods for regression testing in which all the tests in the existing test bucket or suite should be re-executed. This is very expensive as it requires huge time and resources.

Regression Test Selection
Instead of re-executing the entire test suite, it is better to select part of test suite to be run.

Test cases selected can be categorized as 1) Reusable Test Cases 2) Obsolete Test Cases.

Reusable Test cases can be used in succeeding regression cycles.

Obsolete Test Cases can't be used in succeeding cycles.

Prioritization of Test Cases

Prioritize the test cases depending on business impact, critical & frequently used functionalities. Selection of test cases based on priority will greatly reduce the regression test suite.

If your software undergoes frequent changes, regression testing costs will escalate. In such cases, Manual execution of test cases increases test execution time as well as costs. Automation of regression test cases is the smart choice in such cases.  The extent of automation depends on the number of test cases that remain re-usable for successive regression cycles.

Regression Testing Tools

Following are most important tools used for both functional and regression testing:

Selenium: This is an open source tool used for automating web applications. Selenium can be used for browser-based regression testing.

Quick Test Professional (QTP): HP Quick Test Professional is automated software designed to automate functional and regression test cases. It uses VBScript language for automation. It is a Data-driven, Keyword based tool.

Rational Functional Tester (RFT): IBM's rational functional tester is a java tool used to automate the test cases of software applications. This is primarily used for automating regression test cases and it also integrates with Rational Test Manager.

Oniyosys run regression tests using a suitable combination of automated and manual testing. They are conducted not only during the operational software development stage but also before the release stage into a live environment. Regression testing helps detect major variances that could have serious implications on the revenue, schedule, and company reputation. This type of testing is crucial to the success of application development and upgrades.

1 comment:

  1. Hello,
    The Article on Regression Testing - A crucial step for the success of application development and upgrades is very informative. It give detail information about it .Thanks for Sharing the information on regression testing in detail. Software Testing Services