Abstract-Since its emergence in 1990s, Model-Based Safety Assessment (MBSA) has enjoyed significant interest from both academia and industry. The last decade has seen not only the development of a number of methods, techniques and tools, but also the gradual adoption of MBSA techniques by industry and its acceptance by regulators. However, the field of MBSA encompasses a large number of fundamentally dissimilar techniques. This paper presents a simple classification schema for MBSA techniques based on two criteria -provenance of the model and engineering semantics of component dependencies captured by the model. The classification organizes the existing techniques into a number of coherent families. Applicability, limitations and challenges of most prominent families of MBSA techniques are presented, and some of the common challenges faced by MBSA discipline are discussed.