Development of an integrity measure for heavy rail systems
Large scale complex systems require monitoring to ensure that they are able to provide continuous services into the future. Existing integrity measurement techniques determine instantaneous measures of whether a system meets its operational parameters which is insufficient as the measure needs to both incorporate the transitory nature of problems as well as locality-based effects. An analysis methodology has been developed that, with an understanding of the composite nature of the system, can provide an indication of the system integrity. This analysis examines the effect of failure events on the operational state of the system. Observed or predicted events are then collected into a summary value that reflects the operational availability of the system combined with durations where the system was in a compromised state. Therefore, the analysis provides an important link between low-level failures and the effect on a system's operation once redundancy and adaptation have taken effect.