Introducing automated systems (functional) testing to a project used to run manual functional and regression tests at the end of every development cycle is not a technical issue – well, it is to some extent, but there are good solutions out there – it is a fundamental change to the work your testers perform.
In the manual approach a typical set up of roles dictate that test designers create written test specifications in some tool or in ordinary documents. The specifications contain everything the tester needs to execute the test, including detailed step-by-step instructions. The tests are then manually executed over and over again making sure to catch any regression in the system functionality.
When moving to automated testing the previously text based test specifications are transformed into an executable format. Perhaps the behaviour driven approach is used with some short textual description that underneath is connected to code exercising the system, preferably through the GUI if such exists. Since execution of the tests is automated the testers previously doing the manual test execution are no longer needed. Instead test implementers, with the ability to build the code that executes the tests, are working alongside the test designers. Tests are executed by the build system, perhaps nightly or even more frequent making the feedback loop faster.
This is a big change - and yes, it is a good one - but it is important to understand the impact to the organization of your test/project team and the new skills required. It is also important to understand that the automated tests are now a fundamental artifact for your system, just like the written test specifications used to be, and it is to be owned by the test lead. Just because it is automated and uses code to run, it is not to be handed over to the developers.