While an occasional breakdown or even a severe disruption on a very rare occasion is tolerable, Transport Minister Lui Tuck Yew said yesterday that he was "most upset" with the rail situation in the last few weeks.
The recent disruptions have come as a setback after a year when rail reliability seemed to be improving.
Yesterday, Members of Parliament asked about what was being done to fix a rail system bugged by both disruption and security problems.
Government Parliamentary Committee for Transport chairman Cedric Foo (Pioneer) zeroed in on the five disruptions between Feb 23 and March 3, as well as Monday's shutdown of the Bukit Panjang LRT.
He asked for a progress report on the implementation of recommendations made by the Committee of Inquiry after the 2011 breakdowns as well as when the system could "return to stability".
Mr Gan Thiam Poh (Pasir Ris-Punggol GRC) said commuters' "trust in the reliability of our MRT system has been severely tested" while Mr Liang Eng Hwa (Holland-Bukit Timah GRC) described the LRT incident as a "major disappointment".
Mr Seng Han Thong (Ang Mo Kio GRC) and opposition MP Sylvia Lim (Aljunied GRC) wanted to know what was being done to improve the security of the system given the recent break-ins and track intrusions.
Minister Lui conceded that the recent series of rail incidents had "undermined confidence in the public transport system".
"It's something that we will need to work hard to rebuild, and I give you my full assurance that we will be watching this very, very closely," he said.
He said that it had been "a long and difficult journey to claw our way back to a position where we can say that reliability has improved some".
Last year, the public transport operators made significant inroads in improving reliability, he said.
The number of train withdrawals on the North-South and East-West lines halved to 1.1 per 100,000 train-km, from 2.2 in 2013, while delays on the same lines lasting more than five minutes fell to 1.3 per 100,000 train-km, from 1.6 in 2012, he noted. Even the Bukit Panjang LRT's train withdrawal rate had fallen to 4.5 per 100,000 car-km, from 6.1 in 2012.
But Mr Lui admitted that there was "much more we need to do".
Indeed, there were 12 major breakdowns of more than 30 minutes each last year - 50 per cent more than in 2013, and the highest number in at least four years.
Mr Lui said that operators must intensify their maintenance, undertake more predictive and preventive measures and improve overall processes.
On security, the minister also said "we can and must do better", in the light of the recent intrusions, which Ms Lim said were fortunately not terrorism-linked.
On the Bukit Panjang LRT saga, Mr Lui said there would be a "systemic health check". That included investigating whether the trains added recently had anything to do with Monday's electrical fire.