South Australia Premier Mike Rann has announced a major reshuffle to "freshen up" cabinet and the state’s public service.

The shake-up involves two thirds of cabinet ministers changing posts or taking on additional portfolios.

The most notable change is Jennifer Rankine’s appointment to the new portfolio of Minister for the Northern Suburbs. She will also take on the role of Minister for Families and Communities, Housing, Ageing and Disability.

New chief executives have been appointed to six departments: Premier and Cabinet, Families and Communities, Trade and Economic Development, Water, Land and Biodiversity Conservation, Further Education, Employment, Science and Technology, and the Environmental Protection Agency (EPA).

The Premier’s chief executive Warren McCann moves to the role of Commissioner for Public Employment, replacing the retiring Jeff Walsh. Scott Ashby has been appointed chief executive of Water, Land and Biodiversity Conservation, replacing Rob Freeman who now heads up the independent Murray-Darling Basin Authority.

Joslene Mazel moves to the role of Chief Executive of Families and Communities, replacing the retiring Sue Vardon.

Ray Garrand and Brian Cunningham are trading positions, with Garrand taking over Further Education, Employment, Science and Technology, while Cunningham moves to Trade and Economic Development.

Former executive director of Housing SA, Helen Fulcher has been appointed chief executive of the EPA.