Bruce Bonyhady, who was the inaugural chairman of the NDIS, is aghast the Morrison government remains committed to introducing an assessment model universally slammed by the disability community.

He believes the independent assessment policy will undermine the scheme.

"It cannot possibly identify individual needs," Professor Bonyhady told ABC radio on Thursday.

The government wants to replace typical NDIS support packages, based on funding approved for participants with similar circumstances, to personalised budgets based on independent assessments.

The disability community fears independent assessments are nothing more than a cynical cost-cutting exercise, shifting decisions on support packages from medical experts to anonymous bureaucrats.

Disability Minister Linda Reynolds has indicated the government is pushing ahead with introducing independent assessments later this year.

She is adamant the changes will make the NDIS sustainable in the long term.

Prof Bonyhady is concerned attempts to save money on administrative costs will create a false economy.

"An absolute foundation of the scheme is best quality planning and if that takes a little bit longer and costs a little bit more, it actually contributes to the sustainability of the scheme," he said.

He said the "robo-planning" proposal had fuelled enormous outrage, disquiet and unanimous opposition.

"The government needs to go back to the drawing board," he said.

"It also needs to have a much more open dialogue with the disability community and engage in real consultation and real co-design."

Australian Associated Press