Multi-Fragmental Markov Models of Information and Control Systems Safety Considering Elimination of Hardware-Software Faults
Vyacheslav Serhiiovych Kharchenko, Yuriy Ponochovnyi, Artem Boyarchuk, Anton Andrashov · 2019
The information and control systems of Nuclear Power Plant and other safety critical systems are considered as a set of three independent hardware channels including online testing system. Nuclear Power Plant information and control systems design on programmable platforms is rigidly tied to the V-model of the life cycle. Functional safety and availability during its life cycle are assessed using Markov and multi-fragmental models. Multi- fragmental models are used to assess the availability function and proof test period. The multi-fragmental model MICS31 contains an absorbing state in case of hidden faults and allows evaluating risks of “hidden” unavailability. The MICS41 model simulates the “migration” of states with undetected failures into states with detected faults. Results of multi-fragmental modeling (models MICS31 and MICS42) are compared to evaluate proof test period taking into account requirements for SIL3 level and limiting values of hidden fault probabilities.