Darren Lehmann was appointed as the new coach of the Australia cricket team on Monday after Mickey Arthur was sacked just 16 days before the first Ashes Test in England following several embarrassing on and off-field incidents.
"The timing is far from ideal but we didn't feel we could sit back and hope matters would change without addressing issues critical to a high-performing team culture," Cricket Australia chief executive James Sutherland told a news conference in Bristol, southwest England.
"It obviously isn't the type of change we want to make three weeks out from the Ashes commencing but we believe a change is needed. The status quo is not good enough, we need improved accountability and performance."
"This has been a difficult decision to make but one that we feel is necessary," he said.
Sutherland said they were looking to establish a "high-performing" team that was also consistent but recent results had not been good enough.
"To achieve that, we need all the parts moving in the right direction. Recent on-field results have been too inconsistent," he told reporters.
"Discipline, consistency of behaviour and accountability for performance are all key ingredients that need to improve. And we see that the head coach is ultimately responsible for that.
"The Cricket Australia board decided yesterday (Sunday) that Mickey Arthur should not continue as head coach of the Australian cricket team.
"In taking this decision, the board accepted the recommendation to make an immediate change as being in the best interests of the team."
Sutherland also confirmed that Australia captain Michael Clarke, currently sidelined with a back injury, would stand down as a selector.
Former Australia batsman Lehmann was already in England as coach of the second-string Australia A side and has a good track record in coaching with Queensland, Brisbane Heat and in the Indian Premier League.
He played 27 Tests and 117 one-day internationals and is regarded as one of cricket's shrewdest thinkers, although Sutherland insisted Lehmann was not a "silver bullet" who could be expected to turn things round instantly.
South African Arthur, the first foreign-born coach of the Australian team when appointed in November 2011, appeared to have paid the price for a 4-0 Test series loss in India, a poor Champions Trophy campaign and a lack of discipline within the team.
This culminated with an incident which saw David Warner punch England's Joe Root in a bar in Birmingham, central England, earlier this month.
England hold the Ashes and will be looking to win their third successive Test series over arch-rivals Australia -- something they last achieved in the 1950s -- when a five-match campaign starts at Nottingham's Trent Bridge ground.