Jargon buster

PPM - Public Performance Measure: The proportion of trains arriving at their final destination on time. This is defined as arriving within five minutes of planned timetable for London & South East, Regional and Scotland and or within ten minutes for Long Distance operators.

MAA - Moving Annual Average: This reflects the proportion of trains on time in past 12 months. In Q4, the MAA also represents the PPM for the financial year. A higher score equals better performance.

CaSL - Cancellations and significant lateness: The percentage of trains that caused significant disruption to at least some passengers. The Moving Annual Average reflects the proportion of trains cancelled or significantly late in the past 12 months.

A train is considered to be significantly late if it calls at all booked stations, completes its entire booked journey, and arrives between 30 and 119 minutes after the scheduled arrival time at the final destination.

A part cancellation is when a train covers more than half the scheduled mileage and either fails to run the complete journey or failed to stop at any station on the way. Trains completing their journey but arriving at their final destination by more than 120 minutes or more also count as part-cancelled.

A train is considered a full cancellation if it covers less than half the scheduled mileage, or does not run at all. A train failing CaSL also fails PPM. FDM - Freight Delivery Metric: The percentage of freight trains arriving at their destination within 15 minutes of scheduled arrival time. They are only considered to have failed FDM where the delay is caused by Network Rail. Freight’s MAA reflects the proportion of trains meeting FDM in the past 12 months.

In Q4, the MAA also represents PPM for the financial year. A higher score equals better performance.