Around 140 Corrections staff will lose their jobs if a restructure proposal goes ahead.
The department's chief executive Ray Smith says up to 2 per cent of its workforce will have their roles disestablished if the move to unite its prisons, rehabilitation and probation units under one umbrella proceeds.
The affected areas are primarily in management roles in national and regional office as well as support staff.
Mr Smith says under the planned structure the new unit would be responsible for the day to day management and rehabilitation of all offenders across the country.
"Our aim is to make our communities safer by lifting our performance. To do this I need a clear line of sight to my staff on the front line and I need to empower them to make good decisions. After all they know their communities best.
"The proposed new structure will enable us to work together to co-ordinate the management of each offender at every stage and address the underlying causes of their offending," Mr Smith said in a statement on Thursday.
He said each of the three operations currently had its own processes, infrastructure and support staff and the changes would stop duplication of resources.
It was anticipated the proposal would save around $10 million a year.
Other changes would give regional managers the power to make decisions without referring to the national office.
Staff affected by the changes are being consulted and Corrections aims to have the new structure in place by August.