Safety critical large scale systems are complex, physically extensive socio-technical systems, extending over a range of domains, and are of interest because of the enormous catastrophic potential on their constituents, bystanders and the environment. Often, failures in such systems are traced to human error, as well as to unforeseen and unanticipated combinations of causal factors arising from the size, scope and complexity of the systems. Technologies developed to support these systems are often distributed, supporting subsystems with specific local requirements.