The doctoral project is carried out in collaboration between the University of Oslo and DNV GL, funded under the Industrial Ph.D. scheme of the Norwegian Research Council (project number 251396). Furthermore, the research is conducted in close collaboration with the research-based innovation centre Big Insight, also funded by the Norwegian Research Council (project number 237718). The thesis is a collection of five papers. The papers are preceded by an introductory part providing background, context and motivation for the work. Contents Preface i List of publications iii Contents iv IV Towards a framework for assurance of autonomous navigation systems in the maritime industry V Explainable Artificial Intelligence: How Subsets of the Training Data Affect a Prediction v