Within the last few decades, there has been an exponential growth in technologies and process interdependencies within organisations. The period has additionally witnessed accelerated incidences of disasters. Despite operating with tightly interdependent processes and complex technologies where failures could potentially result in disasters, high reliability organisations have continued to record high levels of performance in organisational reliability and safety. Given the increasing havoc wrecked by disasters on organisations, people, and the environment, a framework is required to transfer learnings from high reliability organisations to diverse organisations. This research investigates the extent to which the reliability of organisations can be measured, and the extent to which this measurement can be applied to diverse organisations. Research on high reliability organisations have been mostly conducted through theoretical abstraction and mostly performed in single organisations, with little empirical evidence to support the generalizability of the conclusions. They have been mostly reactive, analysing incidents after the fact, often with retrospective predictability. This research used a mixed methods approach to study eight organisations, in three industries. It combined the objectivity of the survey strategy with the subjectivity of in-depth interviews to obtain balanced data sets that best serves its exploratory nature. It proposed the organisational reliability maturity model that defines baseline measurements and tracks the progression of organisations through different maturity levels. It developed a framework for organisational reliability maturity to identify organisational maturity levels, predict improvement or regressive potentials, benchmark organisations, and develop processes for organisational learning and performance improvement. This research expands existing knowledge in organisational research and opens up new areas of knowledge. It enhances the standardisation and generalisability of the high reliability organisation theory. It enables benchmarking, organisational learning and performance improvement. Finally, it eliminates the retrospective predictability of incidents causative factors and enhances the ability of organisations to predict the potential for incidents. It is hoped that these would help to make organisations more resilient, reduce incidents and disasters, and ultimately safeguard humanity.