Navy personal stand on the HMAS Waller, one of six Collins class submarines of the Navy's Force Element Group
(Image: AAP/Brendon Esposito)

Major defence projects are still running more than 20% behind schedule, the Defence Department has no understanding of how many people are working on them, and major recommendations from both the auditor-general and Parliament remain ignored years later, the Australian National Audit Office (ANAO) has found.

Every year at the request of Parliament's Joint Committee of Public Accounts and Audit, the ANAO checks Defence's homework on a list of major projects to look at financial performance, schedule performance and risk management. This year, 21 projects worth $58 billion were examined, including the F-35, the now-abandoned submarine project and the dumped MRH90 Taipan helicopters.

The projects in the Major Project Report were a total of 405 months late, or 23%, with the chief offender being the already seven-years-delayed and trouble-plagued Taipan helicopters, which incurred another six-month delay before being abandoned last week.