Former WA premier Colin Barnett says the National Disability Insurance Scheme was rushed and his government took a cautious approach to keep the state separate from it.
Mr Barnett, who remains a backbencher since the Liberals' March election loss, said similar to Victoria, WA had a devolved model where about 70 per cent of state funding for disability services was delivered through not-for-profit organisations.
"Victoria and Western Australia could probably acclaim to have the most devolved and the most developed disability service area," Mr Barnett told 6PR radio on Wednesday after calling the station.
"All the states agreed that we should have a consistency across Australia, that we should have the same levels of eligibility, entitlement, transferability (and) funding."
Mr Barnett said WA and Victoria wanted to keep local management but NSW and Queensland did not have such a well-developed system.
"The attitude of those two states to the Commonwealth was 'you take it'," he said.
Mr Barnett claimed the then Prime Minister Julia Gillard threatened to walk away from the NDIS but did not mean it.
"What struck me was that the prime minister wasn't aware that 80 per cent of disability services were actually funded by the states," he said.
"I think that's the problem, that the Commonwealth were seeing it as their scheme."
Mr Barnett said it was not a black and white situation.
"I can understand the current Labor (WA) government thinking 'should we just fall into the national scheme ... or should we keep it a little bit separate?'" he said.
"I took a cautious view that we should stay separate and make sure that we don't disrupt services.
"It was quite a chaotic situation at that time and decisions were certainly being rushed."
Nulsen Disability Services chief executive Gordon Trewern said while the WA model still needed "a fair bit of tweaking", WA should continue its course over three years, then make a decision.
No one disputed the concept of a national scheme but it had to be well designed and implemented, he said.
Mr Trewern said the NDIS was not meeting its targets, there were vacancies in senior management and he believed the cost would blow out.
"The ambitious time frames are not achievable," he said.
