Bækgaard, LarsReichert, ManfredStrecker, StefanTurowski, Klaus2019-05-062019-05-062007978-3-88579-213-0https://dl.gi.de/handle/20.500.12116/22184We discuss two experiments in which requirements engineering techniques has been used and evaluated. In the first experiment a technique called Executable Use Cases is applied in the development of an IT system for public utility services. In the second experiment a technique called Activity Cases is applied in the development of an IT system for a public library. For each experiment we discuss the lessons that we have learned. We use the lessons to scetch a plan for future research in terms of a set of scenarios for combined use of Executable Use Cases and Activity Cases.enText/Conference Paper1617-5468