Assessment of the Reliability of Fault-Tolerant Software:
A Bayesian Approach
The paper by Bev Littlewood, Peter Popov, Lorenzo Strigini, was accepted
for presentation at the SAFECOMP'2000 in October 2000 in Rotterdam, Holland.
The paper appears in the proceedings published in the 'Lecture Notes in
Computer Science', No. 1943, ISBN 3-540-41186-0, pp. 294-308, Springer-Verlag.
Therefore the access to the full text as a .pdf
file is restricted. An abstract from the submission is given below.
Abstract
Fault tolerant systems based on the use of software design diversity
may be able to achieve high levels of reliability more cost-effectively
than other approaches, such as heroic debugging. Earlier experiments have
shown that the reliabilities of multi-version software systems are more
reliable than the individual versions. However, it is also clear that the
reliability benefits are much worse than would be suggested by naive assumptions
of failure independence between the versions. It follows that it is necessary
to assess the reliability actually achieved in a fault tolerant system.
The difficulty here mainly lies in acquiring knowledge of the degree of
dependence between the failures processes of the versions. The paper addresses
the problem using Byesian inference. In particular, it considers the problem
of choosing a prior distribution to represent the beliefs of an expert
assessor. It is shown that this is not easy, and some pitfalls for the
unwary are identified.
Page maintained by: Peter Popov
Last modified 30 January 2001.