The head of the Bureau of Statistics has apologised for poor judgment and testing the patience of Australians during the 2016 census, and revealed that the failure of the digital system cost taxpayers $30 million.
Reading from a prepared statement at the start of a Senate estimates hearing, David Kalisch said he wanted to thank the Australian population for "their forbearance and diligence" in completing the census which was taken offline at what would have been the peak period for submitting forms.
"The ABS tested the patience and commitment of many households especially through the difficulties accessing the call centre and the unavailability of the census online form for nearly two days," he said.
"We made a difficult decision to take the system off line on August 9 to ensure the security of census data, but we should not have got to that point, and the system should have been robust to denial of service events."
"The ABS made a number of poor judgments in our preparation for the 2016 census that led to the poor service experienced by many households. I apologise to the community on behalf of the ABS and I repeat that apology sincerely again today."
Mr Kalisch revealed that while the move to a predominantly digital rather than paper-based census had been intended to save $100 million, the attempts to recover from the system shutdown cost another $30 million, cutting the net saving to $70 million.
"We have to date probably incurred additional costs of around $20 million ... and we anticipate possibly spending another $10 million," Mr Kalisch said.
The census website suffered a further denial of service attack after it had been put back on line, one the Bureau and its contractor IBM put a lot of effort into successfully repelling.
The Bureau also badly handled its bid to retain the names submitted with the census, which had previously been disposed of after processing.
It allowed only three weeks for comment and received only three submissions.
"I think it's probably fair to say there should have been a longer consultation process," he said. "We should have planned that better."
Ninety six per cent of households appear to have completed the census, more than the target of 93.3 per cent, but a full accounting won't be possible until March or April next year.
Fifty eight per cent completed the forms on line, much less than the target of 65 per cent.
Prime Minister Malcolm Turnbull has ordered an inquiry into the census to determine "which heads will roll and when".
Mr Kalisch was appointed to the $705,030 post in 2014. He will appear before a specially-convened Senate inquiry into the census next week.In The Age and Sydney Morning Herald