The Central Bank is this week continuing to press Ulster Bank to resolve the situation surrounding its technical problems, which have left the bank's tens of thousands of customers seriously inconvenienced.

Now into the eighth day of the crisis, the bank has said that clearing the build-up of interrupted transactions has been taking significantly longer than expected and customer accounts are not likely to be fully operational until the end of this week.

The original technical problem was caused by a software upgrade to the payment processing system, which was corrupted. The glitch has disrupted salary transfers, direct debits and social welfare payments, causing a delay in processing certain payments to customers' bank accounts. Ulster Bank has said it is continuing to work around the clock to clear this backlog.

The fiasco demonstrates just how vulnerable the financial system is to a major computer breakdown but also begs the question about whether major banks have a Plan B in place should such an eventuality arise. Electronic payments now govern our lives and, when they are disrupted, the knock-on consequences are serious for both individuals and businesses, particularly if the interruption is protracted.

At long last, the Central Bank has now stepped in and has ordered all banks to review their contingency plans and payment systems. In a bid to ensure such a catastrophic IT failure cannot happen again, both the Central Bank and the Irish Payment Service Organisation (IPSO) are now embarking on a risk assessment review across the country with all banks to avoid a repeat of the disaster.

The Central Bank has requested confirmation from the country's clearing banks that contingency plans are in place, that they are updated and tested regularly.

The risks inherent in the system were confirmed this week when a second bank was hit by a technical problem. Some National Irish Bank customers were unable to carry out online banking and some ATM withdrawals were affected after parent bank, Danske Bank, experienced a technical issue. In this case, however, the issue was promptly identified and a back-up plan put into operation. Identification of the issue to complete recovery of the system took less than three hours.

Enormous pressure is now being applied to Ulster Bank to get back to normal by the end of this week. The Director of Consumer Protection at the Central Bank, Bernard Sheridan, said he expects the bank to stick to commitments given to resolve the problems by the end of this week. He said communication with customers had improved this week but had certainly been lacking last week.

The bank is facilitating customers who call into branches with payslips and giving them cash and is also allowing people to withdraw cash, interest-free, using their credit cards. However, this week presents a particular challenge as many monthly salaries will be processed. Some customers have been advanced payments based on their social welfare entitlements or salaries and as many as 38,000 HSE employees paid through Ulster Bank were being permitted to get an advance of up to €500.

This is the biggest IT failure ever to have occurred at a bank in this country and has had a serious impact on customers. It needs to be resolved as a matter of absolute priority now. After the issue is resolved, customers and the wider public need to be reassured that it cannot happen again, but also need to hear the details of how the fault came about.

Some business and IT experts believe this has been a disaster just waiting to happen, with at least one software expert describing banking IT infrastructure in general as being "glued together by hope". This is not very reassuring if it is true, but what has been instructive in the past week is the deafening silence from Ulster Bank's competitors at a time when they could be capitalising on Ulster's woes and poaching customers with promises of 'it could never happen here'.

Could it be that they are too busy thanking their lucky stars that it was not them hit by this damaging and embarrassing computer failure?