Let's get started by understanding why test automation is needed. Today's agile world needs quick feedback on the code's quality. The developers check-in application code in a source code repository like GitHub. It is imperative that these changes be tested, and the best way to do so is through automation. A test-automation suite can eliminate the mundane work of manual regression testing and can be helpful in finding bugs earlier, thus reducing manual testing time. It can be configured to run at a particular time in the day.

A cut-off time should be provided to the developers, such as 6 P.M. in the evening, by which time they should check in code, get the application build done, and the application deployed to a server like Apache Tomcat. The automation suite may be scheduled to run at 7 P.M. daily. Jenkins is a tool that's used for continuous integration, and so can be used for this purpose.

Advantages of test automation include reducing the burden on the testers doing the manual execution so that they can focus on the functional aspects of the application. Generally, a smoke, sanity, regression test suite is created for this purpose. The advantage of having automatic triggering through Jenkins is that it facilitates test execution in an unattended mode.