Seasprite was the most expensive blunder in the recent history of 28 major Defence Materiel Organisation projects recently reviewed by the Australian National Audit Office.

The office identified a total cost blowout of almost $8 billion and accumulated schedule slippage of almost 119 years for the 28 projects.

Approved in 1996, the year the Howard government came to power, the troubled Seasprite staggered on for 12 years before being euthanased by the then Parliamentary Secretary for Defence Procurement, Greg Combet, in 2008. $1.4 billion of taxpayer's money had been wasted.

Defence personnel had known the project was gravely flawed as early as 1999 or 2000 but nobody told the politicians, Liberal Senator David Fawcett, an ex-army helicopter pilot who worked for the Defence Materiel Organisation before entering politics, said.

He wants a ''more commonsense'' approach so the errors of the past are not repeated over and over again.

Senator Fawcett says Defence needs to advise its political masters of dissenting opinions before decisions are made so alternative points of view can be considered and costly failures averted.

He said it was not uncommon for dissenting opinions on fashionable ideas to come from the experts who were then overruled by bureaucrats and gagged by a defence organisation convention of presenting a consensus view to government.

''The decision makers must have disclosure of the fact that dissent was made and the basis on which the dissenting concerns were dealt with or discarded,'' Senator Fawcett said.

He defended the use of expert consultants, noting ''elections and promotions mean the personality and task-specific competence of individuals holding appointments in executive government and defence will vary over time''.

''Defence is often under media and political pressure to reduce the number of 'consultants and contractors' as a cost-cutting measure,'' he said. ''If the public service or uniformed personnel do not have the required competence this is not only false economy; it directly elevates project risk.''

The Foreign Affairs, Defence and Trade References Committee recently completed an 18-month inquiry into Defence procurement. Its report was highly critical of the way Super Seasprite, landing craft for the now defunct HMAS Manoora and Kanimbla, Wedgetail early warning and (air) control system, Tiger reconnaissance helicopter, Adelaide class missile frigate upgrade, KC-30A Multi Role Tanker Aircraft, Multi-Role Helicopter project, the Air Warfare Destroyer, a $1 billion program to upgrade the armoured personnel carrier fleet, the lightweight torpedo replacement project and Collins class submarine sustainment were managed.

Poor risk assessment and a lack of communication between the Defence Materiel Organisation and the three services were cited as major problem areas.

''Governance of the Australian Defence organisation is dysfunctional,'' he said. ''Defence procurement does not occur in a vacuum. [We should] view Defence through the prism of what we want it to be able to do; not just list [the equipment] we think it should have. This will lead to logical definition of the capabilities needed to generate the military effects required.''

Senator Fawcett has also called for a fair go for Australian defence industries; entities he says have suffered greatly from ''entrenched cultural indifference or even antagonism within Government and Defence''.

''The Defence Materiel Organisation appears to regard industry as having an unending capacity to absorb risk without cost,'' he said.