A botched IT upgrade last week left the NAB’s payment system crippled resulting in chaos for the bank’s customers.
Pensioner and NAB customer Kevin Berthelsen said he had been left disillusioned with the bank after being unable to access his pension until yesterday.
“I have been a customer for 42 years and I am furious at the fact I could not get access to my pension.
“I am sure they did not have any issues with accepting people’s money,” Mr Berthelsen said.
One aspect of the computer glitch involved NAB accounts showing incorrect balances with transactions either duplicated or missing.
NAB customer Warwick Beddoes said his account was one of those affected by the computer failure.
“A few amounts have come out of my account and some amounts credited that are not mine,” Mr Beddoes said.
The bank was eventually able to sort out Mr Beddoes’ account issues.
“All the banks have made big profits so they should be able to sort out problems like this, and they have done so,” Mr Beddoes said.
Last year, the NAB posted a profit of $4.58 billion.
NAB Ruthven Street branch manager Zac McDermott was as much in the dark as some customers.
“We have not really been told or been updated on anything,” Mr McDermott said before referring The Chronicle to the bank’s media department.
NAB spokeswoman Meaghan Telford said the bank had “managed” to identify the problems over the weekend, but could not say when they would be fully rectified.
“We are still working on some account issues and at this stage we anticipate they will be fixed in the near future,” Ms Telford said.
NAB's horror hiccup comes as Australia's big banks wrestle with upgrades to their IT systems, and customers could face more glitches.
Local banks are either replacing or carrying out major updates to their so-called core banking systems, the computers and software which handle fundamental operations like deposit taking, payments and loans.
The NAB began its own billion-dollar core system upgrade project, called NextGen, in 2008, following the CBA which was the first of the four pillars to embark on a core banking system replacement project.
These fundamental computing systems often date back to the 1960s and 70s and have acquired an overlay of extra code to handle banking functions unheard of a generation ago, such as internet banking.
Banks treat major change to core banking systems with trepidation.
Not only are they expensive to replace, with IT transformation bills creeping into the billions, but given the main asset of a core banking system is reliability, playing around with core code can have unintended consequences.
Jorn Bettin, an adviser with IT consultancy International Business Research Services, said a big bank typically had several tens of millions of lines of code to maintain, with between 20 per cent and 50 per cent of it legacy code written in languages no longer taught in universities, such as Cobol. As the Cobol-trained programming workforce headed into retirement, the pool of knowledge around core banking systems was drying up, leaving banks increasingly exposed.
"We will see more such events," said Mr Bettin of NAB's recent woes. "There are plenty of accidents waiting to happen."
Mr Bettin said these incidents weakened trust in the banking industry.
"Incidents like the NAB system meltdown provide a beautiful illustration of the business case for replacing traditional code and system specifications by formal models," he said.
System problems were also likely to bedevil banks as they went about renewing their legacy systems, he said.
Software validation and testing standards were higher in healthcare and aviation and banks needed to lift their game, although he conceded the costs were high.
"The amounts needed to validate are really huge," he said.