Written by James Royal, Performance Strategy Manager at South Western Railway
Between Sunday 23 and Saturday 29 February 2020, South Western Railway achieved performance of 86 per cent.
It was the first time this year that we had improved our performance two weeks in a row – up from 78 per cent in the week commencing Sunday 9 February and 79 per cent in the week commencing Sunday 16 February.
But, while it is a sign that we are gradually improving, some people quite rightly asked, what does performance of 86 per cent actually mean? And importantly, how is it measured?
Every second counts
Every time you board (or, in some circumstances, fail to board) a SWR train, we are monitoring the performance of our services. The punctuality of every one of our trains is recorded. Throughout the day, every day of the year – even Sundays and public holidays.
The information that we collect is reported on through a range of ‘performance metrics’. These metrics not only help you keep us accountable, but also help us pinpoint exactly where – and how – we need to improve.
Public performance measure or PPM
When we talk about performance, we often talk about ‘public performance measure’ or ‘PPM’.
PPM is the percentage of services that arrive at their final destination within five minutes of the advertised time, having stopped at all scheduled stations.
The other week, when we announced that we had achieved performance of 86 per cent, this meant that 86 per cent of all our services that week arrived at their final destination within five minutes of their advertised time.
We recognise that there is more work to do to improve our performance, but for context, 86 per cent is about six per cent better than the week prior and about four per cent better than roughly the same week this time last year.
Right time
Of course, we don’t just want to get our passengers to their destinations within five minutes of advertised times, but rather at the ‘right time’. When we talk about ‘right time’, we are referring to a service that arrives either early or within one minute of its advertised time.
Between 2 February and 29 February 2020, for example, 51 per cent of our services arrived at the ‘right time’, up from 43 per cent between 5 January and 1 February. With 93 per cent having arrived within 15 minutes of their advertised time, we are working hard to see many more services arriving at the right time.
Lateness and cancellations
If a service arrives more than one minute after its advertised time, we consider it late. Any service that arrives more than 30 minutes after its advertised time, we consider significantly late.
And, when it comes to cancellations, we don’t just consider those that fail to start their journey as being cancelled, but also any services that fail to call at any stations on route as planned – known as ‘part cancellations’.
With this in mind, between 2 February and 29 February 2020, 5.6 per cent of our services were considered cancelled or significantly late (CaSL), down from 7.2 per cent between 5 January and 1 February.
Improving performance
These metrics are just a handful of those that help us pinpoint exactly where – and how – we need to improve.
Recently, for example, as part of our Joint Performance Improvement Centre with Network Rail, our stations team now has access to live information about station
platforms.
This detail allows the team to verify any ‘dwell improvements’ made due to changes in the way they manage busy platforms. As a result, the station ‘dwell’ reduces by a few seconds each time.
It may not sound like much, but in an environment where every second counts, it is important.
So, next time you’re travelling, know that we are monitoring your train’s performance.
We are committed to providing a reliable and punctual service for our passengers. We know there is more to do, but the data indicates that we are making gains.
