Organizations tend to limit their investment in test automation due to the lack of information on the actual tests reuse and when will automated tests really pay off. However, to perform efficient regression testing of software systems, it is expected from a development team to posses a certain level of test automation infrastructure in place, where at the minimum the test execution is scripted and automated. In this paper we are proposing the usage of record & replay approach to observe the functional usage of a component under test, while its being invoked as part of the whole system or only in a certain portion of it. Afterwords, executable tests are automatically derived, containing both test inputs and test verdict, allowing its later usage as part of a regression testing. With as minimal effort as one manual test execution, developers are provided with automated tests, minimizing any concerns on the investment in automation. A case study from Bombardier Transportation is provided showing how the proposed approach substantially reduced the test effort needed when performing regression testing of the train control management system for the Stockholm C30 metro train.