Title
A new modeling approach to the safety evaluation of N-modular redundant computer systems in presence of imperfect maintenance
Abstract
A large number of safety-critical control systems are based on N-modular redundant architectures, using majority voters on the outputs of independent computation units. In order to assess the compliance of these architectures with international safety standards, the frequency of hazardous failures must be analyzed by developing and solving proper formal models. Furthermore, the impact of maintenance faults has to be considered, since imperfect maintenance may degrade the safety integrity level of the system. In this paper, we present both a failure model for voting architectures based on Bayesian networks and a maintenance model based on continuous time Markov chains, and we propose to combine them according to a compositional multiformalism modeling approach in order to analyze the impact of imperfect maintenance on the system safety. We also show how the proposed approach promotes the reuse and the interchange of models as well the interchange of solving tools.
Year
DOI
Venue
2009
10.1016/j.ress.2009.02.014
Reliability Engineering & System Safety
Keywords
DocType
Volume
Safety,N-modular redundancy,Bayesian Networks,Imperfect maintenance,Multiformalism modeling
Journal
94
Issue
ISSN
Citations 
9
0951-8320
0
PageRank 
References 
Authors
0.34
0
4
Name
Order
Citations
PageRank
Francesco Flammini116319.53
Stefano Marrone217425.49
Nicola Mazzocca367478.37
valeria vittorini433933.14