The South Australian government will need to deliver on its planned spending cuts and savings to achieve its forecast budget surpluses, the Australian Industry Group says.

In its first budget since the March election, the government has forecast a modest surplus of $48 million in 2018/19, rising to $211 million by 2021/22.

The results will hinge on rising GST returns, but also on the government’s ability to deliver savings worth $864 million over the next four years.

“While last year’s anticipated surplus did not materialise, there is no doubt that future budget estimates have been assisted by previously unbudgeted GST growth,” Australian Industry Group SA head Stephen Myatt said.

“For the budgeted surpluses to be achieved, the government will also have to deliver on its efficiency targets,”

As well as the planned savings, the government has budgeted to spend $11.3 billion on infrastructure projects over the next four years along with extra spending in health and education.

It will also cut the jobs of more than 4000 full-time public servants, though about half of those positions are expected to be transferred to non-government organisations.

Both the Labor opposition and SA Unions have slammed the cuts, arguing they will affect the delivery of crucial services.

But Business SA said the government should be praised for moving to reform the state’s “expensive” public service as the Property Council praised the infrastructure spend as a way to create jobs across the construction sector.

“If you’re a chippie, sparkie, plumber, landscaper, architect, engineer or conveyancer, the infrastructure investment made through this budget is welcome news,” the council’s SA executive director Daniel Gannon said.