  Model-based safety assessment has been one of the leading research thrusts of
the System Safety Engineering community for over two decades. However, there is
still a lack of consensus on what MBSA is. The ambiguity in the identity of
MBSA impedes the advancement of MBSA as an active research area. For this
reason, this paper aims to investigate the identity of MBSA to help achieve a
consensus across the community. Towards this end, we first reason about the
core activities that an MBSA approach must conduct. Second, we characterize the
core patterns in which the core activities must be conducted for an approach to
be considered MBSA. Finally, a recently published MBSA paper is reviewed to
test the effectiveness of our characterization of MBSA.
