An Approach to Address Safety as Non-Functional Requirements in Distributed Vehicular Control Systems

Abstract

Distributed vehicular control systems include several safety-critical processes so that reliability aspects are of growing importance, raising concerns about faults affecting them. Observing this fact, this paper presents a combination of aspect-oriented concepts to model faults in early-design phases of distributed vehicular control systems. A fault modeling approach in communication protocols as non-functional requirements—NFR is proposed, using aspect-oriented modeling (AOM) with the support of the Real-Time From Requirements to Design using Aspects (RT-FRIDA) framework. Following practical experiments about the effect of electrical fast transients in vehicular control systems, a study was performed specifying NFR associated with these faults. Then, an evaluation with a SIG graph using the softgoal weight method and the NFR framework is presented to validate the proposed approach. The results emphasize that early fault modeling could improve the control system modeling mapping fault behaviors in order to mitigate and diagnosis the fault impact in critical tasks. The approach cover gaps related to fault modeling and allow requirements specification with AOM concepts emphasized in the case study by the correlation among network performance degradation and requirements related to faults. The analysis with the softgoal weight method also provides an alternative view of the impact of fault modeling in vehicular critical real-time systems.