Citation

Yang Q, Tian J, Zhao T. Safety Sci. 2017; 93: 162-177.

Copyright

(Copyright © 2017, Elsevier Publishing)

DOI

10.1016/j.ssci.2016.12.006

PMID

unavailable

Abstract

Most of accidents have increasingly been considered as emergent phenomena from variability and interactions in socio-technical systems, but even the contemporary safety research is still far from understanding why or how the emergent phenomena appear and develop. The perspective of functional resonance (as a form of emergence) provides intriguing and important insights into this issue, in spite of the insufficiency of explanation for how the resonance occurs when the variability in multiple performance coincides in certain scenarios, and the lack of an approach that manifests the functional resonance so as to assist with hazard identification. We attempt to illuminate this problem by expanding the paradigm of Functional Resonance Analysis Method (FRAM), with the promise of a comprehensive approach by means of formal verification tool SPIN. The approach focuses on modeling of system functions, formalization of functional variability and interactions, and verification whether the preset safety requirements are violated. It contributes to the realization that the hazards caused by functional resonance can be identified, with detailed manifestations about the way that the coincidence of functional variability occurs and ultimately leads to an accident, as well as effective safety measures to damp the resonance. Highlighting emergence as an important source of hazards in complex systems, this contribution aims to facilitate hazard identification with increased rigor and efficiency. The approach is applied to a developing Air Traffic Management (ATM) system where the Minimum Safe Altitude Warning (MSAW) is introduced, i.e., MSAW-in-ATM system, illustrating that the multiple locally-small variability (that of providing surveillance data, modeling terrain and obstacles, and terrain conflict alert confirmation) brings large effects to global performance of the system. This case exemplifies how to achieve a successful design improvement, during development of the system, based on the comprehension of system safety vulnerable to the complex emergence.

Language: en