Victoria renewed a $700 million contract for its controversial myki transport card without doing a review of the eight-year-old, much-maligned system.
That's partly because the premier's department couldn't find the original business case.
A damning auditor-general's report released on Thursday said Public Transport Victoria was told to do a "post-implementation review" comparing the business case with what myki actually delivered.
Instead, operators NTT Data won the process to run the system again until 2023, and the review wasn't started until seven months later and is still ongoing.
"This means that the new myki contract, which came into effect 1 January 2017, has not been informed by the lessons from a PIR, even though it could have been," Victorian Auditor-General Andrew Greaves said in his report.
PTV told the auditor-general it was unable to verify with the premier's department if a document it had from 2004 was the original business case.
When Myki was rolled out across Melbourne in 2010 it was more than $500 million over budget, behind schedule and without the promised option of single-use tickets.
It still has no mobile website or app to allow commuters to easily top up their accounts.
