Assessing the Reliability of Diverse Fault-Tolerant
Systems
"Assessing the Reliability of Diverse Fault-Tolerant Systems"
by Bev Littlewood, Peter Popov, Lorenzo Strigini was presented at
the INuCE'2000, International Conference on Control and Instrumentation
in Nuclear Installations, Bristol, UK, 2000. The paper abstract is
given below. The full text is available for download as a .pdf
file.
Abstract
Design diversity between redundant channels is a way of improving the dependability
of software-based systems, but it does not alleviate the difficulties of
dependability assessment. Assuming failure independence between channels
is unrealistic. Using statistical evidence from realistic testing, standard
inference procedures can estimate system reliability, but they take no
advantage of a system’s fault-tolerant structure. We show how to extend
these techniques to take account of fault tolerance by a conceptually straightforward
application of Bayesian inference. Unfortunately, the method is computationally
complex and requires the conceptually difficult step of specifying 'prior'
distributions for the parameters of interest. This paper presents the correct
inference procedure, exemplifies possible pitfalls in its application and
clarifies some non-intuitive issues about reliability assessment for fault-tolerant
software.
Page maintained by: Peter Popov
Last modified: 30 January 2001