Transport Minister Steven Joyce says KiwiRail has assured him there won't be any more budget blowouts with its projects.
The Cook Strait ferry Aratere will resume service this week after being refurbished and lengthened by 30 metres in Singapore.
The project cost the state-owned company $53 million, more than $10 million over budget.
The 13-year-old ship required much more work than was expected, including a new power management system.
KiwiRail chief executive Jim Quinn says the problems of the Aratere project will not be repeated as they have learnt from them.