Tutorial on Design diversity
In November 1997 a tutorial on software design diversity was given
by Bev Littlewood and Lorenzo Strigini for the staff of UK Nuclear Electric.
The presented material has later been revised, extended with some recent
results and a paper "Modelling software design diversity - a review"
by Bev Littlewood, Peter Popov, Lorenzo Strigini, will appear in ACM
Computing Surveys in 2001. It can be accessed as a .pdf
file. An abstract from the submission is given below.
Abstract
Design diversity has been used for many years now as a means of achieving
a degree of fault tolerance in software-based systems. Whilst there is
clear evidence that the approach can be expected to deliver some increase
in reliability compared with a single version, there is not agreement about
the extent of this. More importantly, it remains difficult to evaluate
exactly how reliable a particular diverse fault-tolerant system is. This
difficulty arises because assumptions of independence of failures between
different versions have been shown not to be tenable: assessment of the
actual level of dependence present is therefore needed, and this is hard.
In this paper we survey the modelling issues here, with an emphasis upon
the impact these have upon the problem of assessing the reliability of
fault tolerant systems.
Page maintained by: Peter Popov
Last modified 31 January 2001.