Former Department of Health boss Martin Bowles has called for the public service to embrace a permission culture, giving employees the chance to try new approaches without fear of "crucifixions".
In a valedictory address to the Institute of Public Administration in Canberra, Mr Bowles reflected on 40 years in the public service, including high profile controversies such as the Rudd government's home insultation scheme and the backlash to Abbott government budget cuts.
He said a permission culture would give departments and agencies the ability to innovate and succeed.
"What I mean by that is [an environment] where people are prepared to try different things and not be worried.
"One where, if things go wrong, there's no crucifixions held at dawn or dusk.
"Things do go wrong, quite regularly in fact. The real thing is how do we get ourselves through it, how do we change that dynamic?
"If you create a culture where people feel like they have permission to do things, you can get anything done."
A former Immigration Department secretary and deputy secretary at Defence, Mr Bowles announced in August he would join the Calvary Health Care network.
The move followed reported differences with Health Minister Greg Hunt.
A royal commission found the $2.7 billion home insultation scheme, which included the deaths of four people, was not properly designed or implemented.
As deputy secretary in the former Department of Climate Change and Energy Efficiency, Mr Bowles said he saw first hand the impact on public servants.
Public service leaders should remind their colleagues of significant failures to avoid repeating past mistakes, he said.
"You would hope that we would never get to another home insulation issue but it is entirely possible if we as public servants don't do our job properly.
"We had providers wanting to beat us, we had suppliers wanting to beat us, we had home owners wanting to beat us.
"I said 'this is the best professional development you ever get' and they thought I was stupid. But it was.
"It taught them a whole range of things they would have never ever have got anywhere else."
Mr Bowles said he had been "absolutely smashed" in the immediate aftermath of Tony Abbott and Joe Hockey's controversial 2014 budget, which included plans to charge a $7 co-payment for patients visiting their doctor and cuts to rebates for short appointments.
The plan was killed off in 2015 after months of controversy
"The media, Senate estimates, everyone wanted a victim," Mr Bowles said.
"I kept saying, 'I'm the secretary, I'll get it right next time".
"We got it wrong. Me bashing to death the person or persons, and there were quite a few persons involved in this issue, was not going to help.
"They knew they buggered it up, they didn't do it again and I didn't say anything."
Praising ministers Greg Combet, Chris Bowen and Scott Morrison for their support of public servants, Mr Bowles said he would miss Canberra and would never rule out returning to government.
"The integrity of the public service has to be uncontestable," he said.
"With the ever changing world that we are currently in, I think we need it more than ever."
