Towards security requirements: Iconicity as a feature of an informal modeling language

Self-adaptive systems need to be designed with respect to threats within their operating conditions. Identifying such threats during the design phase can benefit from the involvement of stakeholders. Using a system model, the stakeholders, who may neither be IT experts nor security experts, can identify threats as a first step towards formulating security requirements. To support it, the modeling language might possess adequate features to support this task. This paper investigates how iconic signs as a feature of an informal modeling language can contribute to eliciting security requirements by non-experts. Taking urban grid as a case, we relate benefits and specifics of using iconic signs to the two modeling challenges: i) reducing the cognitive complexity required to understand and model a system by non-experts, and ii) facilitating the threat identification activity using a system model. Outputs of three experiments suggest that iconic signs do assists in addressing the challenges.