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.