ANDREWS, J.D., 2006. Measures of component contribution to the failure of phased missions. IN: Guedes Soares, C. and Zio, E. (eds). Safety and reliability for managing risk : proceedings of the European Safety and Reliability Conference (ESREL 2006), Estoril, Portugal, 18-22 September. London : Taylor & Francis, pp. 1555-1560.
This paper develops measures which identify the contribution to system failure when the system
operates a phased mission. The measures developed are the equivalent of Birnbaum’s measure of importance
and the criticality measure of importance in a conventional analysis. It is assumed that during the mission
the system components cannot be repaired. In the determination of the importance measures the
contribution to phase failure is considered in two aspects: failure during the phase (phase importance) and
failure on transition to a phase (transition importance). Component importance measures indicate the contribution
to phase and overall mission unreliability.