Transport minister Humza Yousaf said today it would be "all shoulders to the wheel" for ScotRail to turn round its performance after recent major disruption in Edinburgh and Glasgow.
It came as he published the full 249-point improvement plan which the operator has been ordered to complete to return punctuality to "acceptable" levels.
Mr Yousaf also said improvements to the Scottish network would be more rigorously scrutinised before being approved, in an attempt to prevent a repeat of the runaway costs of current schemes.
The minister declined to speculate as to whether train punctuality in the current four-week period would show an improvement or deterioration.
However, he said it would be "all shoulders to the wheel" in the wake of significant disruption in Glasgow last week, and after a train broke down near Haymarket in Edinburgh two weeks ago.
Punctuality in the year to 12 November was 89.8 per cent - 0.5 percent points below the acceptable level,
Mr Yousaf also warned that poor weather could hit performance.
He said: "There will be times where there are seasonal dips.
"Disruption will happen when the weather is bad or when it is cold."
However, he added: "ScotRail should be lifting performance where they can. We want to see continual improvement."
The improvement plan, which was published in summary last month, includes upgrades to trains and the early replacement of signalling equipment before it wears out.
There is also a focus on ensuring "golden trains" - services likely to cause the greatest disruption if delayed - run on time.
The minister was speaking at Waverley Station in Edinburgh as he inspected an electric train which has been upgraded as part of a £19 million programme which started last year.
It includes new heated couplers on the Class 334 fleet - which run on a secondary Edinburgh-Glasgow line via Bathgate - which enable extra carriages to be added more quickly to busy trains.
Earlier, Mr Yousaf announced a crackdown on the cost of major upgrades to the network after several large projects, including the Edinburgh-Glasgow main line electrification, went significantly over budget.
He said schemes would in future only be given the go-ahead once there was a "full understanding of costs".
He told the annual Scottish Rail Conference in Edinburgh, organised by Mackay Hannah, that funders had previously been a "hostage to fortune" in the face of rising costs.
The change will come for the next Network Rail spending period, from 2019.