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
