we used to have lots of problems along the Grantham to Retford stretch, then when N/R took over from Railtrack, Network Rail introduced Local worksite Inspectors, who checked the workmanship of the area maintenance staff "contractors", each inspector worked on his/her discipline (Power supplies, Telecom, Signals, Track)
it took time but after the first year the workmanship & reliability improved, but the day we took the "contractors" in house all the Local Worksite inspectors lost their jobs
one day we can't trust these "contractors" the next day they are totally trust worthy
now when we have incidents who checks-- its the area maintenance guys supervisor, will he drop his men in it ?
as a lad the older hands told me lots of things, here's a few about maintenance
"every new guy shaves a bit off how he maintains the equipment, so over the years standards drop"
"when I joined maintenance standards were up here now there down here"
"if you are taught by a good bloke you have half a chance, if taught by a bad one you have no chance"
and the most telling was a senior manager & his head supervisor were talking about the interviews they just held for a leading hands post, "these blokes don't even know what an SI is for" HA HA HA HA, I said "But they have worked for you for years" "yes but their useless HA HA HA"