Abstract
Systems engineering requires a good understanding of user needs. For security systems, the potentially large number of threats and the diverse conditions that a product may experience can create practical challenges for those in charge of developing system requirements. The complexity involved in carrying out this task can be reduced by using a set of attack scenarios as a basis for the analysis. However, developing scenarios that can accommodate relatively large multidisciplinary teams also presents its own challenges. In order to address this point, the authors have created and implemented a simple framework for requirements development: The proposed iCARE method has been tested and validated through the FP7-funded RIBS project.