There's really no competition for travellers between "our" various lines - so the comparisons of who's faring better or worse are academic to a great extent. However, it is worthwhile using one another as benchmarks.
At yesterday's TransWilts
AGM▸ , one of the slides presented showed a current performance chart across each of the areas, allowing us to get a feeling of Cotswold v Thames Valley v South Wales to South Coast (our Westbury hub services) versus West Country branches. Page 15 of Dan Okey's presentation at
http://www.firstgreatwestern.info/coffeeshop/index.php?topic=19577.msg236776#msg236776 .
Ppm measures are against the timetabled plans for each day, so the starting point (100% performance) is not the published National Rail timetable from January to May, but rather the the planned service after disruption caused by the Newbury and other blockades have been taken out. Looking at what the means with a TransWIlts service, for example, it means that although our normal service is 18 single journeys per day, the performance measure for last week would have classified just 7 journeys as 100% and the ppm figure quoted is based on degradation from 7 rather than from 18.
Dan Okey's presentation - do take a full look - also considers issues and measures being taken to address them. Perhaps not in the slides - confirmation that class 1 trains get priority over class 2; lots of people steaming about where freight should (and has been) fitting in the priority tree.