The decision to modernize its business applications was made five years ago but the university didn't want to go through the pain of ripping and replacing existing systems, or tackle a costly rewrite.
As a result the ANU chose to migrate off the mainframe onto a server-based platform to avoid any unpredictable outcomes or disruptions.
Originally, there were six critical applications running off the mainframe. All of these applications had been created in-house.
But in 1999, ANU implemented PeopleSoft for finance, HR and student administration.
This meant there was only two applications remaining on the mainframe which was hard to justify when it came to costs.
According to ANU's director of corporate information services, Rick van Haeften, the cost of staying on the mainframe was just too high.
"We were paying six figure sums annually just for licensing, and then there was the staff," he said.
"It prompted us to move as quickly as possible. It's hard to justify when you are only hosting two core applications.
"But the moving cost wasn't as significant as we first envisaged. This is because we made the decision about how much data conversion was really required and how much could be archived."
One of the remaining applications was the core Parking Infringements Management System (PIMS), based on Software AG's Adabas and Natural technology, which had been operating since the early 1980s.
There was also an in-house developed records management system.
"The challenge was maintaining the integrity of the information during the move," van Haeften said.
"The main cost during the move was maintaining two in-house developers who were focused on the project for three months. In total I think it cost us less than A$80,000 (US$62,700)."
Migrating PIMS to a server based platform has enabled the ANU to retain all of the system's functionality and value, according to van Haeften.
"Software AG completed a seamless migration for PIMS within five weeks, with no loss of functionality during the migration period," he said.
Based in Canberra, the university has more than 18,000 users including 13,000 students drawn from 94 countries.