ANDREWS, J.D. and BEESON, S., 2003. Birnbaum’s measure of component importance for noncoherent systems. IEEE Transactions on Reliability, 52(3), pp 301-310
Importance analysis of noncoherent systems is limited,
and is generally inaccurate because all measures of importance
that have been developed are strictly for coherent analysis.
This paper considers the probabilistic measure of component
importance developed by Birnbaum (1969). An extension of this
measure is proposed which enables noncoherent importance analysis.
As a result of the proposed extension the average number
of system failures in a given interval for noncoherent systems
can be calculated more efficiently. Furthermore, because Birnbaum’s
measure of component importance is central to many
other measures of importance; its extension should make the
derivation of other measures possible.