It is modelled on the Westminster system, meaning that the highest ranking members of the executive are drawn from an elected state parliament.

Specifically the party or coalition which holds a majority of the House of Assembly (the lower chamber of the South Australian Parliament).

Governance in the colony was organised according to the principles developed by Edward Wakefield, where settlement would be conducted by free settlers rather than convicts.

[7] In 1850 the British Parliament passed the Australian Constitutions Act 1850, which empowered the Legislative Council to alter its own composition.

The Legislative Council responded by passing the Constitution Act 1856, which created a bicameral parliament and an executive responsible to it.

[6] Boyle Finniss was appointed the first Premier of South Australia as part of an interrim executive until elections to the new Parliament could be held in 1857.