Evolutionary Risk Analysis: Expert Judgment

New systems and functionalities are continuously deployed in complex domains such as Air Traffic Management (ATM). Unfortunately, methodologies provide limited support in order to deal with changes and to assess their impacts on critical features (e.g. safety, security, etc.). This paper is concerned with how change requirements affect security properties. A change requirement is a specification of changes that are to be implemented in a system. The paper reports our experience to support an evolutionary risk analysis in order to assess change requirements and their impacts on security properties. In particular, this paper discusses how changes to structured risk analysis models are perceived by domain experts by presenting insights from a risk assessment exercise that uses the CORAS model-driven risk analysis in an ATM case study. It discusses how structured models supporting risk analysis help domain experts to analyse and assess the impact of changes on critical system features.