Going back onto the subject of self-install, its really not all its cracked up to be in my experience.
When I moved to Be I was left without a phone line for several days as due to it being self-install, nobody checks the line works at the customers premises after doing the jumpering at the exchange. I was told the problem was a faulty tie-pair, so it seems nobody bothered to even check it was working where it leaves the exchange either.
Then when I moved to Origin Broadband on Digital Region EXACTLY the same thing happened again, except this time of course the error was at the street cabinet.
I must point out that from what I can gather the engineer did exactly as described on the job sheet. The problem is that did not factor in the potential for the instructions being wrong about which jumper block my line was fitted at.
So Wednesday I was disconnected first thing in the morning, by Thursday evening both me and my ISP knew my E side had been incorrectly jumpered to someone elses house as they had tried calling my number and left a message on the persons answering machine. Of course neither of us could get that message across to Openreach due to the amount of bureaucracy between the parties involved.
By Saturday the other persons line had been repaired, but mine was left hanging (turns out literally, my line had been completely disconnected and left loose in the cabinet) until Monday.
Granted the last case was made over-complicated due to the shared architecture, but the biggest delays was Openreach saying it must be Digital Regions cabinet that was faulty. Openreach outright refused to come out and double check it wasn't their fault, Digital Region actually sent out engineers to their cabinet TWICE on connection day to prove everything was working there.
In both of these cases if they had been engineer installs, the problems would have been fixed in minutes rather than days as the engineer would have found there was a problem immediately.