Antifragility: systems engineering at its best

Abstract

Systems engineering has emerged because of the growing complexity of systems and the growing need for systems to provide a reliable service. The latter has to be defined in a wider context of trustworthiness and covering aspects like safety, security, human–machine interface design and even privacy. What the user expects is an acceptable quality of service (QoS), a property that is difficult to measure as it is a qualitative one. In this paper, we present a novel criterion, called assured reliability and resilience level (ARRL) that defines QoS in a normative way, largely by taking into account how the system deals with faults. ARRL defines 7 levels of which the highest one can be described as the level where the system becomes antifragile.