Combining STPA with PF Requirements Analysis: Taking the Insulin Pump Problem as an Example

The Problem Frames (PF) approach has gained significant attention and recognition in the field of requirements engineering. However, most of the existing work focuses on modeling normal behaviors in systems and lacks safety considerations and analysis. Therefore, it is crucial to integrate problem-oriented requirements analysis methods with modern safety analysis approaches. In this paper, we propose an approach which combines the PF requirements analysis method with the System-Theoretic Process Analysis (STPA), to identify hazardous control actions, loss scenarios, and safety requirements, and formally validate the identified results using the model-checker UPPAAL. The aim is to incorporate safety requirements early in the requirements modeling phase. A case study of an insulin pump control system demonstrates the applicability and viability of this method.