The phrase "a cost overrun" is correct and usable in written English.
It can be used when discussing a situation where expenses exceed the budgeted amount for a project or task.
Example: "The construction project faced a significant cost overrun due to unexpected delays and material price increases."
Alternatives: "budget excess" or "financial overage".
It is not needed, there is very likely to be a cost overrun and what benefits it brings will not be delivered until after the project is completed in 10 years' time.
There was a cost overrun, too: "At the same time, it became clear that extensive renovations — including the addition of a seventh floor — would have been necessary to create the type of world-class facility that the U.S.G.A. sought to establish.
"We're not pleased that we have a cost overrun," he said.
A cost overrun on the $1billion fixed-price contract could have wiped out what was then a small company, but the contract proved to be the companys salvation.
ITER is a hugely exciting project, but we couldn't continue with the situation where every time there was a cost overrun, the research budget was raided [to plug the gap].
A cost overrun on the $1 billion fixed-price contract could have wiped out the company, but the railcars were delivered on time, and Bombardier came away with a tidy profit of about $100 million before tax.
Capturing the value identified in exploration is challenging due to the risk of: (a) cost overruns and (b) late delivery.
But the report warns of a $7 billion cost overrun and a 1- to 3-year delay in completing the project, which includes cooperation from Russia, Europe, Japan, and Canada.
Attempts to fast track construction resulted in a $16 million cost overrun, resulting in a final cost of $97.7 million and an eight-month delay in its completion.
But its new technology caused major problems, with a $1.5 billion cost overrun on the Astute-class program and a 43-month delay in the Astute's launching.
Those changes erased most of a $4.8 billion cost overrun on the station.
