Notes and methodology
Public Performance Measure (PPM):
 
PPM was introduced on 6 June 2000 to give a better indication of the actual performance of Britain’s passenger railways. It replaced the Passenger’s Charter as the main means of measuring passenger train performance. The Passenger’s Charter is still used for season ticket refunds.
 
PPM combines figures for punctuality and reliability into a single performance measure. Unlike the Charter, it covers all scheduled services, seven days a week. PPM measures the performance of individual trains against their planned timetable. This may differ from the published timetable (see below). PPM is therefore the percentage of trains ‘on time’ compared to the total number of trains planned.
 
A train is defined as on time if it arrives within five minutes (i.e. four minutes 59 seconds or less) of the planned destination arrival time for London and South East and regional services; or ten minutes (i.e. nine minutes 59 seconds or less) for long-distance services. A higher score is better.
Cancellations and Significant Lateness (CaSL):
 
CaSL is a combined measure of punctuality and reliability.  It is a percentage measure of scheduled passenger trains which are either cancelled (including those cancelled en route) or arrive at their scheduled destination more than 30 minutes late.  Scheduled passenger trains are based on the planned timetable which is agreed at 22:00 the day before.  The CaSL measure is the same for all sectors and a lower score is better.
 
Right Time Performance (RTP):
 
RTP is a combined measure of punctuality and reliability.  It is a percentage measure of scheduled passenger trains which are arrive early or within 59 seconds of schedule.  Scheduled passenger trains are based on the planned timetable which is agreed at 22:00 the day before.  The RTP measure is the same for all sectors and a higher score is better.
Average Lateness:
 
Average lateness measures the average lateness of a passenger as they alight from their train. It is calculated for each train by multiplying the number of passengers expected to alight at main stations by the punctuality to the nearest minute at those stops.

If a train is cancelled, Network Rail multiply the number of expected passengers by 1.5 times the service frequency on that route. Average lateness does not account for the effect of missed connections.
 
 
Where a train fails to run its entire planned route, calling at all timetabled stations, it will either be shown as cancelled (if it runs less than half its planned mileage) or will be added to the trains in the ‘30 minutes or more’ lateness band and will be included in the CaSL measure. Trains which complete their journey as planned are measured for punctuality at their final destination. A train’s performance is generally recorded by the automated monitoring systems which log performance using the signalling equipment.
 
As described above, the PPM compares the actual performance of the train service with the plans held in the computer systems. These plans, technically called ‘plan of the day’, are usually the same as the published timetable with amendments reflecting pre-published engineering amendments. The performance is quoted against the published timetable or, where appropriate, emergency timetables that may be introduced where the published timetable is rendered inoperable by changes to the speed restrictions, flooding or other unanticipated events.
 
 
 
Source: Network Rail
Network Rail Outputs/Indicators - Key statistics

Notes and methodology
Delay minutes
 
Delay minutes are a performance measure for punctuality of passenger and freight trains. A delay is defined as a loss of time against a schedule between two consecutive locations on the train’s journeys.
The delay minutes quoted here are Network Rail delay minutes only. Delay minutes attributed to Network Rail could be due to some of the following: infrastructure related issues, timetable and operation of the network or external events which impact on the network.
 
All delays to scheduled passenger and freight trains are included within the measure – delays to empty coaching stock (ECS) and light locomotive moves are excluded.  Only delays on Network Rail owned network are included.

Freight Delivery Metric (FDM):
 
Freight Delivery Matric (FDM), developed for CP5 to be generally similar to the Public Performance Measure (PPM). FDM allows freight journeys to measure their performance in a similar manner to the PPM, which provides an indicator of performance for Britain's passenger railways.  
 
This measure for deriving FDM differs from PPM as there is a uniform measure for the entire freight network; each train being 'on time' if it arrives at its final destination within 15 minutes of its scheduled arrival time. It only covers delay caused by Network Rail. A higher score is better.
Light Maintenance Depot Stewardship Measure (LMDSM):
 
The score is calculated by assessing the asset remaining life of key elements of a depot by visual inspection and combining into an overall station score. The scale represents the remaining life, as a percentage of the expected life, of all measured assets at a station, on a scale of 1-5. It has been adopted as a standard method for assessing the condition of a variety of asset types. A lower score is better.
 
Asset Management Excellence Model (AMEM):
 
The Asset Management Excellence Model (AMEM) measures an organisation’s asset management capability by assessing its maturity in a range of core asset management activities. The AMEM tests the existence, completeness, effectiveness and integration of these activities and is applicable to any organisation operating in an asset intensive, highly regulated
environment.
 
A higher score is better and a score of over 70% is needed to be in the excellent category.
Asset Data Quality
 
Asset data quality is assessed using confidence grading of data
reliability (the process or ‘governance’ for producing the data: A (best practice) to D (poorest governance) scale) and a grading of accuracy and completeness (1 (>= 99%) to 6 (< 50%)).

In order to demonstrate a comparable year on year forecast of data
governance (the alpha element of the Network Rail confidence grading
methodology) this forecast has been measured against the level of
governance that would represent A grade governance in 2017/18 for
plain line and S&C track assets. The numeric measure of accuracy
within the confidence grade is based upon a lowest value method of
aggregating attribute level accuracy to a system level result. As such,
the forecasted accuracy measure represents the lowest single result of
any attribute that forms part of the system.

Asset data quality for signalling, telecoms, buildings, structures, and
earthworks will be reported from the 2015 Delivery Plan onwards.
Electrical power will be reported from the 2016 Delivery Plan onwards.
Stations Stewardship Measure (SSM):
 
The SSM is an average condition rating of each station where trains make timetabled stops and Network Rail is the operator or the Landlord. A lower score is better.
 
The score is calculated by assessing the asset remaining life of key elements of a station by visual inspection and combining into an overall station score. The scale represents the remaining life, as a percentage of the expected life, of all measured assets at a station, on a scale of 1-5. It has been adopted as a standard method for assessing the condition of a variety of asset types.
 
Source: Network Rail
Network Rail Outputs/Indicators - Key statistics

Notes and methodology
Railway periods CP5
 
The Outputs and Indicators key statistics report are now presented periodically to be in line with the Network Rail Monitor.
Possession disruption (PDI)
 
Possession disruption index (PDI) measures the extent of planned disruption to passenger and freight services caused by engineering works on the network.  This measure is broken down into passenger disruption index (PDI – P) and freight disruption index (PDI – F).  PDI is weighted by passenger volumes and values of time when possessions take place.  Freight is weighted by the number of freight movements.  The index is compared against the possession disruption in 2007-08.
 
Note:
 
An error has been detected in the calculation of PDI-P.  This calculation error has existed since the PDI-P measure was created and has been reported consistently on this basis for Control Period 4 (April 2009 to March 2014) and Control Period 5 (April 2014 to March 2019) to date.  However the error is not considered to be material as it impacts the target and actual reported number in equal measure.  On this basis, Network Rail will continue to report against the existing target for the remainder of Control Period 5.  If this measure continues to be reported in Control Period 6 (April 2019 to March 2024) Network Rail intend to correct the calculation error for both target setting and future reporting
 
Network Rail has informed us that the Possession Disruption Index for Passengers (PDI-P) is continuing to have calculation issues, and had been unable to report this measure in periods 1 to period 4.  Network Rail is developing a proposal for an alternative network availability measure, which ORR will assess.
Year 2
 
2015-16 Period dates
  Start date End date
Period 1 01/04/2015 - 02/05/2015
Period 2 03/05/2015 - 30/05/2015
Period 3 31/05/2015 - 27/06/2015
Period 4 28/06/2015 - 25/07/2015
Period 5 26/07/2015 - 22/08/2015
Period 6 23/08/2015 - 19/09/2015
Period 7 20/09/2015 - 17/10/2015
Period 8 18/10/2015 - 14/11/2015
Period 9 15/11/2015 - 12/12/2015
Period 10 13/12/2015 - 09/01/2016
Period 11 10/01/2016 - 06/02/2016
Period 12 07/02/2016 - 05/03/2016
Period 13 06/03/2016 - 31/03/2016
Year 3
 
2016-17 Period dates
  Start date End date
Period 1 01/04/2016 - 30/04/2016
Period 2 01/05/2016 - 28/05/2016
Period 3 29/05/2016 - 25/06/2016
Period 4 26/06/2016 - 23/07/2016
Period 5 24/07/2016 - 20/08/2016
Period 6 21/08/2016 - 17/09/2016
Period 7 18/09/2016 - 15/10/2016
Period 8 16/10/2016 - 12/11/2016
Period 9 13/11/2016 - 10/12/2016
Period 10 11/12/2016 - 07/01/2017
Period 11 08/01/2017 - 04/02/2017
Period 12 05/02/2017 - 04/03/2017
Period 13 05/03/2017 - 31/03/2017
For a break down of railway periods, please see the control period 4 and control period 5 dates table here.
 
Source: Network Rail
Network Rail Outputs/Indicators - Key statistics