Why a week they ask?
Well, you’ve to sort our flights for your engineer who lives and works near your repair centre in England, you’ve to ask him/her if they’re prepared to fly to Ireland with tools that could be lost in baggage (remember, no tools in hand baggage anymore). Then arrange travel from the airport to the site, with the possibility that the Engineer will not be back in time for the return flight, so you’ve now accommodation to book (just in case).
And then there’s the cost, try and find a cheap flight at a moments notice, there’s no such thing, so your paying over the odds for the flight, car hire, engineers expenses, shipping of parts to site (the Engineer won’t want to carry a spare till for example) plus the car hire that the booking of the hotel (just in case).
Because of the expense you’d much rather wait and see if there is going to be another fault logged to at least make it worth your while. But it doesn’t happen. And you’ve waited long enough, and the client is on the phone completely dissatisfied with your level of service, but you’ve no option, you can’t run to the cost of setting up an office and sourcing engineers.