The first initiative, announced by Minister for Defense Stephen Smith and Minister for Defense Materiel Mike Kelly, involves replacing obsolete components of the vessels' Integrated Ship Control Management and Monitoring System.
The system currently aboard the six-vessel fleet was designed in the 1980s.
Work will be conducted in two phases -- one ship first, with the remaining five submarines to follow.
According to the Department of Defense, Australian firm ASC Pty Ltd. will work with Saab Systems to engineer replacements for the obsolete system components.
The contract value for the first phase is about $62 million, the Defense Department said. The value of second-phase work was not disclosed.
Under a second initiative, availability of the submarines will be improved by reducing planned full-cycle docking periods for each submarine from three years to two years, with more efficient logistic support arrangements, implementation of performance-based maintenance contracts and development of a revised approach to the program of planned maintenance and usage.