This document intends to give guidance about how to demonstrate the safety of complex systems.
The reader should get an understanding of why:
- complex systems require a different approach compared to simple systems
- quantitative reliability does not represent safety adequately in complex systems
- different system models must be used in the analyses of complex systems
- a systems approach is necessary to understand the behaviour of complex systems
- objectivity is essential in handling any system artefact
The reader should get an understanding of what:
- kind of assurance aspects are essential for creating confidence that the systems behave safely
- kind of system aspects must be addressed to understand system behaviour, that is, according to the “CESM metamodel”
- kind of capability any analysing method should possess when dealing with complex systems.
- a safety argument is
The reader should get an understanding of how:
- complex systems differ from simple systems
- complexity arises in systems
- analysis of the behaviour of complex systems at different levels of abstraction can be done to identify:
- safety requirements
- scenarios for how systems may become unsafe
- to merge the above requirements with safety requirements originating from regulations
- objectivity, knowledge, and arguments are related
- evidence and reasoning can build knowledge to underpin the truthfulness of claims
- grounds for justified confidence can be created to show that the:
- identified requirements are adequate
- requirements are fulfilled.