First thing to remember: the Swiss are very service-minded and have always prided themselves in their ability to provide an efficient operation. Only the Japanese are able to match them. The reason why others can't do it is because they don't - and never will - have that particular Swiss mentality. You need to work with the regularity of a Mondaine clock, which is never going to happen in the UK or Ireland....or Germany, for that matter.
Second thing: Swiss transport timetables work because they don't try to be over-ambitious. On the railways, the Swiss don't try to cram in more trains than the route capacity can realistically handle, unlike the British. Hence it is easier to stick to the timetable because there's less to potentially go wrong. Having said that, outside factors can undermine the system, which is why SBB has taken to barring some German services from entering the Swiss network simply because the Germans have - over the last 35 years - lost their ability to be punctual to the extent that German rail services are often worse than UK ones. A late-running DB train can have quite an undesirable knock-on effect.