WITH A RECORD NUMBER OF NEW TRAINS DUE TO ENTER SERVICE IN 2020, ROGER FORD CONSIDERS THE IMPACT OF RELIABILITY ON PERFORMANCE
Just how much does rolling stock reliability matter? Matter, as in affecting service performance. There is a school of thought, promoted by highly experienced and capable engineers with fleets towards the lower end of the reliability ratings table, that once you get to around 15,000 Miles per Technical Incident (MTIN), rolling stock reliability is no longer a major factor in the Public Performance Measure (PPM). However on an increasingly congested network, with dwell times under pressure and PPM, with its five or 10 minutes windows, now replaced by right time, the potential disruption from a train failing is clearly more serious than ever before.
Of course, it is the knock-on effect of the Technical Incident (TIN), not the failure itself, which damages performance. A TIN is registered by the TRUST train reporting system after a train has stopped for three minutes. What happens after that is measured by the Primary Delay Minutes, which record only the delay to the affected train.
In Period 7 2019-20, for example, eight fleets averaged more than 30 delay minutes per incident (D…
