Please make sure your review is not just focused on inputs from business & consultancy from companies with a vested interest in deriving revenue from the government. The reportedly $10B bill for IT services is not an indication of the complexity of government services but more a reflection of the total reliance on vendors to deliver a service that is not well understood.
Disruptive solutions have been staggeringly successful in recent years as their approach to challenging the status quo relies on streamlining & simplification rather than generating revenues from doing the work. This in itself is a transformative approach, diametrically opposed to the business culture in corporate Australia.
Using blockchain as an infrastructure technology to manage core information shared across all departments might be a good start as they all deal with the same customers. Having a national customer database would then facilitate many applications to extend the functionality to individual departments, specific to their responsibilities. Having a consolidated view of the data is even more beneficial and, privacy considerations aside, is the key to streamlining government support.
Proposing wholesale transformation is unrealistic, as is asking the foxes to repair the henhouse.
Good luck in your endeavours.