Model-based safety evaluation of automation systems (MODSAFE): MODSAFE summary report

The objective of the MODSAFE project is to evaluate and develop methods based on formal model checking and apply them in the safety analysis of NPP safety automation. In the first project year a review of formal methods and models for safety evaluation of industrial and nuclear safety systems was made, basic methodology for applying model checking to safety evaluation was developed, and the feasibility of the approach was studied using two case examples. This work was based on using techniques developed for hardware model checking and the case studies employed the NuSMV model checking tool. In the second project year methodology for using timed automata as a basis for model checking safety systems was developed and a more elaborate case study involving also failure models was completed. The results show that by using current model checking techniques it is possible to verify whether a design model of a moderate size safety system satisfies its key safety requirements or not, even when system failures must be taken into account.