Synthesizing Behavioral Model of Event-Based Requirements

Problem Statement: in the software engineering field, satisfaction of user's requirements by software has been a matter of concern. Therefore, monitoring software behavior against user's highlevel requirements has already received a considerable and significant attention. However, the gap between low-level software behavior and high-level requirements has put an obstacle in the way of monitoring. Approach: to overcome the obstacle, we presented a method to synthesize a behavioral model of the event-based requirements in three steps: (1) eliciting event-based requirements; (2) specifying the requirements in event-based formulae and (3) mapping the formulae into a behavioral model. Results: to show effectiveness of the method, it was applied to requirements of a safety critical system, called Railroad Crossing Control (RCC) one and a behavioral model was synthesized. The model was used to synthesize monitor of the RCC system. The monitor is responsible for surveillance of software behavior for preventing the collision between the train and some car at the junction of rail and road.Conclusions: we proposed a systematic method started from users' requirements elicitation and concluded with its behavioral specification. Focus of the method was on event-based real-time requirements which were stated by scenarios in a sequence of real-time interactions.