Survey on Safety Evidence Change Impact Analysis in Practice: Detailed Description and Analysis

Critical systems must comply with safety standards in many application
domains. This involves gathering safety evidence in the form of artefacts such
as safety analyses, system specifications, and testing results. These artefacts
can evolve during a system’s lifecycle, and impact analysis might be
necessary to guarantee that system safety and compliance are not jeopardised.
Although extensive research has been conducted on impact analysis and on
safety evidence management, the knowledge about how safety evidence
change impact analysis is addressed in practice is limited. This technical
report presents a survey targeted at filling this gap by analysing the
circumstances under which safety evidence change impact analysis is
addressed, the tool support used, and the challenges faced. We obtained 97
valid responses representing 16 application domains, 28 countries, and 47
safety standards. The results suggest that most projects deal with safety
evidence change impact analysis during system development and mainly from
system specifications, the level of automation in the process is low, and
insufficient tool support is the most frequent challenge. Other notable findings
are that safety case evolution should probably be better managed, no
commercial impact analysis tool has been reported as used for all artefact
types, and experience and automation do not seem to greatly help in avoiding
challenges.