Business correspondent, BBC News
Put together Whitehall and big computer contracts and frequently the result is an overspending nightmare.
The NHS computer project has come in for criticism
With the ongoing NHS computer project, the amber lights seem to be flashing.
The National Audit Office has warned that key parts of the giant IT upgrade programme in England are falling behind schedule.
It said that while it was too early to tell if it gave value for money, significant challenges remained if it was to be completed.
Computer experts have responded by saying they would like to give the government the benefit of the doubt, but with caveats.
"We would like to think eventually it will work - the question is, will it be value for money for the tens of billions spent, and on that the jury is out," said Tony Collins, executive editor of Computer Weekly.
Trouble with new IT systems has caused problems in the past for public services.
In 1999, the issue of new passports was severely delayed because of system glitches.
Queues built up outside passport offices and some holidaymakers missed flights.
- The Criminal Records Bureau got off to a bad start because of backlogs on computer checks.
Thousands of staff appointments in health and education were held up.
- The Child Support Agency (CSA) failed to make payouts because of IT failures. The chief executive quit amidst fierce criticism of the CSA.
So the big question is, why do government departments and agencies struggle to get to grips with these big computer projects when private sector managers seem to take them in their stride?
Graeme Swan, a partner at Ernst and Young, has worked on major public sector IT contracts.
He argues there is nothing intrinsically wrong with the public procurement and implementation process.
But he believes that the scale and number of people involved in these deals makes them hard to handle.
"They are hugely ambitious programmes - it's a complex environment working in government and on top on that you have got many interested groups and parties which you don't find in the private sector," he said.
Take the usual layers of complexity and add in the fact that the NHS computer programme is the biggest of its kind anywhere in the world, and you can see why sceptics wonder whether it will come in on time and on budget.