A note on Functional Diversity
"A note on modelling functional diversity" by Bev Littlewood,
Peter Popov, Lorenzo Strigini was published in "Reliability Engineering
an System Safety", 66, (1999), pp. 93-95. The paper abstract is given below.
Abstract
It has been argued that functional diversity might be a plausible means
of claiming independence of failures between two versions of a system.
We present a model of functional diversity, in the spirit of earlier models
of diversity such as those of Eckhardt and Lee, and Hughes. In terms of
the model, we show that claims for independence between functionally diverse
systems seem rather unrealistic. Instead, it seems likely that functionally
diverse systems will exhibit positively correlated failures, and thus will
be less reliable than an assumption of independence would suggest. The
result does not, of course, suggest that functional diversity is not worthwhile;
instead, it places upon the evaluator of such a system the onus to estimate
the degree of dependence so as to evaluate the reliability of the system.
Page maintained by: Peter Popov
Last modified: 22 March 2000