  Over the last years, we have seen several security incidents that compromised
system safety, of which some caused physical harm to people. Meanwhile, various
risk assessment methods have been developed that integrate safety and security,
and these could help to address the corresponding threats by implementing
suitable risk treatment plans. However, an overarching overview of these
methods, systematizing the characteristics of such methods, is missing. In this
paper, we conduct a systematic literature review, and identify 7 integrated
safety and security risk assessment methods. We analyze these methods based on
5 different criteria, and identify key characteristics and applications. A key
outcome is the distinction between sequential and non-sequential integration of
safety and security, related to the order in which safety and security risks
are assessed. This study provides a basis for developing more effective
integrated safety and security risk assessment methods in the future.
